The cardinals can vote twice Thursday morning and twice in the afternoon. If no one collects a two-thirds majority, the cardinals will return Friday.

The conclave to select the next pope has begun after Catholic cardinals from across the world filed into the Sistine Chapel Wednesday before sealing themselves inside.

One hundred and thirty-three cardinals are sequestering themselves behind the Vatican’s medieval walls for the start of a conclave to elect a successor to Pope Francis.