KIEV, Ukraine (AP) — The Latest on Ukraine's presidential runoff: (all times local):

10:10 a.m.

Corruption and economic stagnation are big issues for voters in Ukraine's presidential runoff.

Lyudmila Potrebko, a 22-year-old computer programmer, cast her ballot for Volodymyr Zelenskiy, a 41-year-old comedian who is challenging President Petro Poroshenko.

She says "I have grown up under the old politicians and only have seen empty promises, lies and corruption ... It's time to change that."

Zelenskiy, 41, got twice as many votes as Poroshenko in the first round three weeks ago. Like his sitcom character, a teacher thrust into the presidency after a video of him blasting corruption goes viral, he has focused on fighting graft, riding the wave of public distrust of Ukraine's political elite.

Many voters in this nation of 42 million are struggling to survive on meager wages and soaring utility bills.

Irina Fakhova, a 55-year-old sales clerk, says "we have grown poor under Poroshenko and have to save to buy food and clothing ... we have had enough of them getting mired in corruption and filling their pockets and treating us as fools."

8 a.m.

Polls have opened in Ukraine's presidential runoff as the nation's incumbent leader struggles to fend off a strong challenge by a comedian who denounces corruption and plays the role of president in a TV sitcom.

Opinion surveys ahead of Sunday's vote have shown 53-year-old President Petro Poroshenko trailing far behind comic actor Volodymyr Zelenskiy, reflecting public dismay with endemic corruption, a moribund economy and a five-year fight against Russia-backed insurgents in the country's east.

Zelenskiy, 41, got twice as many votes as Poroshenko in the first round three weeks ago. Like his sitcom character, a teacher thrust into the presidency after a video of him blasting corruption goes viral, he has focused on fighting graft, riding the wave of public distrust of Ukraine's political elite.

Poroshenko, a billionaire candy magnate before taking office, has relied on traditional political barnstorming, using sympathetic television stations to extensively cover his appearances. Zelenskiy, however, has largely stayed away from the campaign trail and eschewed interviews. He has run his campaign mainly on Instagram, where he has 3.7 million followers.