U.S. President Barack Obama waves as he departs for Ethiopia aboard Air Force One from Jomo Kenyatta International Airport in Nairobi July 26, 2015. Obama told Kenyans on Sunday on his first presidential trip to his father's homeland that there was "no limit to what you can achieve" but said they had to deepen democracy, tackle corruption and end exclusion based on gender or ethnicity. REUTERS/Thomas Mukoya