Officials of the Independent National Electoral Commission trouble shoot card readers after they failed to capture President Goodluck Jonathan's card at his polling unit in Otuoke, Bayelsa State March 28, 2015. Nigerians went to the polls on Saturday in what looks set to be the first genuine electoral contest since the end of military rule in 1999, in which an opposition candidate has a fighting chance of unseating the incumbent, President Goodluck Jonathan. REUTERS/Afolabi Sotunde