Workers put the final touches on a carnival mask bearing the likeness of resigned Petrobras Chief Executive Maria das Gracas Silva Foster are seen at a costume factory in a suburb of Rio de Janeiro February 4, 2015. Foster and other senior management at Brazil's Petrobras resigned on Wednesday amid a festering corruption scandal, unleashing a scramble to find replacements capable of restoring investor confidence in the state-run oil company. REUTERS/Ricardo Moraes (BRAZIL - Tags: ENERGY POLITICS CRIME LAW BUSINESS)