Question: Coverage of which international situation from 2015 earned the Pulitzer prize for the photojournalist Sergey Ponomarev?
{'answer': 'European migrant crisis', 'supporting_facts': [['Sergey Ponomarev (photographer)', 0], ['Sergey Ponomarev (photographer)', 1], ['Sergey Ponomarev (photographer)', 2], ['European migrant crisis', 0]]}