Cadets of the Nakhimov Naval School carry a Russian flag during a ceremony commemorating Russian service members killed in the course of Russia-Ukraine conflict, in Sevastopol, Crimea, February 25, 2023. REUTERS/Alexey Pavlishak 

Cadets of the Nakhimov Naval School take part in a ceremony commemorating Russian service members killed in the course of Russia-Ukraine conflict, in Sevastopol, Crimea, February 25, 2023. REUTERS/Alexey Pavlishak 

A teacher conducts a lesson for school students as they take shelter inside a metro station during massive Russian missile attacks in Kyiv, Ukraine February 10, 2023. REUTERS/Viacheslav Ratynskyi 

School students attend a lesson as they take shelter inside a metro station during massive Russian missile attacks in Kyiv, Ukraine February 10, 2023. REUTERS/Viacheslav Ratynskyi 

School students attend a lesson as they take shelter inside a metro station during massive Russian missile attacks in Kyiv, Ukraine February 10, 2023. REUTERS/Viacheslav Ratynskyi 

School students take shelter inside a metro station during massive Russian missile attacks in Kyiv, Ukraine February 10, 2023. REUTERS/Viacheslav Ratynskyi 

A school student attends a lesson as she takes shelter inside a metro station during massive Russian missile attacks in Kyiv, Ukraine February 10, 2023. REUTERS/Viacheslav Ratynskyi 

A woman and a child look at an artwork of the famous street artist Tvboy, created on a wall of a local lyceum (a school), amid Russia's attack on Ukraine, in the town of Bucha, outside Kyiv, Ukraine January 29, 2023. REUTERS/Valentyn Ogirenko 

A local woman walks with a bicycle while smoke rises from a school building damaged by a Russian military strike, amid Russia's attack on Ukraine, in Chasiv Yar, Donetsk region, Ukraine January 28, 2023. REUTERS/Oleksandr Ratushniak 

Mykola Dziuba and his two friends attend an online class in a makeshift classroom built by them from wooden poles and plastic sheeting on the only hill in the village that catches mobile internet, amid Russia's attack on Ukraine, in the village of Hontarivka, Kharkiv region, Ukraine January 13, 2023. REUTERS/Vitalii Hnidyi TPX IMAGES OF THE DAY 

Mykola Dziuba and his two friends attend an online class in a makeshift classroom built by them from wooden poles and plastic sheeting on the only hill in the village that catches mobile internet, amid Russia's attack on Ukraine, in the village of Hontarivka, Kharkiv region, Ukraine January 13, 2023. REUTERS/Vitalii Hnidyi 

Mykola Dziuba and his two friends pose for a picture before an online class near a makeshift classroom built by them from wooden poles and plastic sheeting on the only hill in the village that catches mobile internet, amid Russia's attack on Ukraine, in the village of Hontarivka, Kharkiv region, Ukraine January 13, 2023. REUTERS/Vitalii Hnidyi 

Gas masks and other debris lie visible at a school that was used as a barracks by occupying Russian forces in the village of Bilozerka, in Ukraine?s southern Kherson region, December 2, 2022. War crimes prosecutors believe around 300 Russian troops were stationed in the building for several months before pulling out in mid-November 2022. REUTERS/Anthony Deutsch 

A Ukrainian serviceman is seen in a destroyed building of a school at a frontline, amid Russia's attack on Ukraine, in Donetsk region, Ukraine January 7, 2023. REUTERS/Anna Kudriavtseva 

A Ukrainian serviceman is seen in a destroyed building of a school at a frontline, amid Russia's attack on Ukraine, in Donetsk region, Ukraine January 7, 2023. REUTERS/Anna Kudriavtseva 

Ukrainian Border Guards receive drawings from school children, among donations of food and gifts from their families and people in general, as Russia's attack on Ukraine continues, in Sloviansk, Ukraine, December 29, 2022. REUTERS/Clodagh Kilcoyne TPX IMAGES OF THE DAY 

Students attend a lesson at an art school during an electricity outage, after critical civil infrastructure was hit by Russian missile and drone attacks, amid Russia's attack on Ukraine, in Kyiv, Ukraine December 23, 2022. REUTERS/Vladyslav Musiienko 

A teacher helps a student during a lesson at an art school amid an electricity outage, after critical civil infrastructure was hit by Russian missile and drone attacks, amid Russia's attack on Ukraine, in Kyiv, Ukraine December 23, 2022. REUTERS/Vladyslav Musiienko 

A student attends a lesson at an art school during an electricity outage, after critical civil infrastructure was hit by Russian missile and drone attacks, amid Russia's attack on Ukraine, in Kyiv, Ukraine December 23, 2022. REUTERS/Vladyslav Musiienko 

Students attend a lesson at an art school during an electricity outage, after critical civil infrastructure was hit by Russian missile and drone attacks, amid Russia's attack on Ukraine, in Kyiv, Ukraine December 23, 2022. REUTERS/Vladyslav Musiienko 

Students attend a lesson at an art school during an electricity outage, after critical civil infrastructure was hit by Russian missile and drone attacks, amid Russia's attack on Ukraine, in Kyiv, Ukraine December 23, 2022. REUTERS/Vladyslav Musiienko TPX IMAGES OF THE DAY 

Communal workers clean an area near a school building destroyed by a Russian military strike, amid Russia's attack on Ukraine, in Kramatorsk, Ukraine December 23, 2022. REUTERS/Oleksandr Ratushniak 

A man is seen at a site of a school building destroyed by a Russian missile strike, amid Russia's attack on Ukraine, in Kramatorsk, Ukraine December 22, 2022. REUTERS/Vitalii Hnidyi 

Destroyed a playground and a school are seen, as Russia's attack on Ukraine continues, in Lyman, Donetsk region, Ukraine December 20, 2022. REUTERS/Oleksandr Ratushniak 

Local residents clean broken windows in a school gym damaged by a Russian military strike, as Russia's attack on Ukraine continues, in Kramatorsk, Ukraine December 17, 2022. REUTERS/Alena Yarysh TPX IMAGES OF THE DAY 

A cadet of the Tyumen Higher Military Engineer Command School wearing a bulletproof vest and carrying an assault rifle competes in a 25-metre race during a winter swimming tournament in Tyumen, Russia December 11, 2022. REUTERS/Alexey Malgavko 

A cadet of the Tyumen Higher Military Engineer Command School wearing a bulletproof vest and carrying an assault rifle competes in a 25-metre race during a winter swimming tournament in Tyumen, Russia December 11, 2022. REUTERS/Alexey Malgavko 

A cadet of the Tyumen Higher Military Engineer Command School wearing a bulletproof vest and carrying an assault rifle gets out of the water after a 25-metre race at a winter swimming tournament in Tyumen, Russia December 11, 2022. REUTERS/Alexey Malgavko 

A cadet of the Tyumen Higher Military Engineer Command School wearing a bulletproof vest and carrying an assault rifle competes in 25-metre race during a winter swimming tournament in Tyumen, Russia December 11, 2022. REUTERS/Alexey Malgavko TPX IMAGES OF THE DAY 

A drawing is seen inside a school building used by occupying Russian troops as a base in the settlement of Bilozerka, amid Russia's attack on Ukraine, in Kherson region, Ukraine December 2, 2022. REUTERS/Anna Voitenko 

Propaganda newspapers are seen inside a school building that was used by occupying Russian troops as a base in the settlement of Bilozerka, amid Russia's attack on Ukraine, in Kherson region, Ukraine, December 2, 2022. REUTERS/Anna Voitenko 

A view shows a school building used by occupying Russian troops as a base in the settlement of Bilozerka, amid Russia's attack on Ukraine, in Kherson region, Ukraine, December 2, 2022. REUTERS/Anna Voitenko 

Students attend a lesson of English language in a classroom at a school, amid Russia's attack on Ukraine, in Kyiv, Ukraine December 2, 2022. REUTERS/Valentyn Ogirenko TPX IMAGES OF THE DAY 

Teacher Tetiana Olifirova conducts an online chemistry lesson in a classroom at a school, amid Russia's attack on Ukraine, in Kyiv, Ukraine December 2, 2022. REUTERS/Valentyn Ogirenko 

Teacher Natalia Kryvoshei conducts an online lesson of a history in a classroom at a school, amid Russia's attack on Ukraine, in Kyiv, Ukraine December 2, 2022. REUTERS/Valentyn Ogirenko 

A junior student runs along a corridor inside a school, amid Russia's attack on Ukraine, in Kyiv, Ukraine December 2, 2022. REUTERS/Valentyn Ogirenko 

Teacher Tetiana Olifirova conducts an online chemistry lesson in a classroom at a school, amid Russia's attack on Ukraine, in Kyiv, Ukraine December 2, 2022. REUTERS/Valentyn Ogirenko 

A teacher conducts a hybrid mathematic lesson for junior students of a private school, amid Russia's attack on Ukraine, in Kyiv, Ukraine December 1, 2022. REUTERS/Valentyn Ogirenko 

Junior students of a private school leave a dinning room, amid Russia's attack on Ukraine, in Kyiv, Ukraine December 1, 2022. REUTERS/Valentyn Ogirenko 

Daria Kosova attends a mathematic lesson at a private school, amid Russia's attack on Ukraine, in Kyiv, Ukraine December 1, 2022. REUTERS/Valentyn Ogirenko 

A view shows a building of a local school destroyed during a Russian missile attack in the village of Novooleksandrivka, in Kherson region, Ukraine November 9, 2022. REUTERS/Valentyn Ogirenko 

Chairs are seen inside a classroom of a local school destroyed during a Russian missile attack in the village of Novooleksandrivka, in Kherson region, Ukraine November 9, 2022. REUTERS/Valentyn Ogirenko 

A view shows a building of a local school destroyed during a Russian missile attack in the village of Novooleksandrivka, in Kherson region, Ukraine November 9, 2022. REUTERS/Valentyn Ogirenko 

An interior view shows a classroom of a local school destroyed during a Russian missile attack in the village of Novooleksandrivka, in Kherson region, Ukraine November 9, 2022. REUTERS/Valentyn Ogirenko 

A view shows a building of a local school destroyed during a Russian missile attack in the village of Novooleksandrivka, in Kherson region, Ukraine November 9, 2022. REUTERS/Valentyn Ogirenko 

A view shows a building of a local school destroyed during a Russian missile attack in the village of Novooleksandrivka, in Kherson region, Ukraine November 9, 2022. REUTERS/Valentyn Ogirenko 

A local resident passes by a school destroyed by Russian shelling, as Russia's attack in Ukraine continues, in Avdiivka, Donetsk region, Ukraine November 7, 2022. REUTERS/Oleksandr Ratushniak 

A view of a school room damaged by Russian shelling, as Russia's attack in Ukraine continues, in Avdiivka, Donetsk region, Ukraine November 7, 2022. REUTERS/Oleksandr Ratushniak TPX IMAGES OF THE DAY 

A Ukrainian national flag and a flag of European Union wave in the wind near a school destroyed by Russian shelling, as Russia's attack in Ukraine continues, in Avdiivka, Donetsk region, Ukraine November 7, 2022. REUTERS/Oleksandr Ratushniak 

A dog stands among debris of a school building destroyed by a Russian air strike in a village near a frontline in Mykolaiv region, Ukraine October 26, 2022. REUTERS/Valentyn Ogirenko 

A view shows a school building destroyed by a Russian air strike in a village near a frontline in Mykolaiv region, Ukraine October 26, 2022. REUTERS/Valentyn Ogirenko 

Ukrainian servicemen stand next to a school building destroyed by a Russian air strike in a village near a frontline in Mykolaiv region, Ukraine October 26, 2022. REUTERS/Valentyn Ogirenko 

A view shows a school building destroyed by a Russian air strike in a village near a frontline in Mykolaiv region, Ukraine October 26, 2022. REUTERS/Valentyn Ogirenko 

A view shows a school building destroyed by a Russian air strike in a village near a frontline in Mykolaiv region, Ukraine October 26, 2022. REUTERS/Valentyn Ogirenko 

A view shows a school building destroyed by a Russian air strike in a village near a frontline in Mykolaiv region, Ukraine October 26, 2022. REUTERS/Valentyn Ogirenko 

A school bus with smashed windows is seen abandoned in a field, amid Russia's attack on Ukraine, in Balakliia, Ukraine, October 22, 2022. REUTERS/Clodagh Kilcoyne TPX IMAGES OF THE DAY 

Friends play football in the playground of the School No. 134 that was destroyed by Russian military strikes, as Russia's attack on Ukraine continues, in Kharkiv, Ukraine, October 14, 2022. REUTERS/Clodagh Kilcoyne 

Friends sit on swings in the playground of the School No. 134 that was destroyed by a Russian military strike, as Russia's attack on Ukraine continues, in Kharkiv, Ukraine, October 14, 2022. REUTERS/Clodagh Kilcoyne TPX IMAGES OF THE DAY 

Friends sit on a swing in the playground of the School No. 134 that was destroyed by a Russian military strike, as Russia's attack on Ukraine continues, in Kharkiv, Ukraine, October 14, 2022. REUTERS/Clodagh Kilcoyne 

Friends play football in the playground of the School No. 134 that was destroyed by Russian military strikes, as Russia's attack on Ukraine continues, in Kharkiv, Ukraine, October 14, 2022. REUTERS/Clodagh Kilcoyne