Heads of state from left to right: Argentina's outgoing President Alberto Fernandez, Paraguay's President Santiago Pena, Brazilian President Luiz Inacio Lula da Silva, Uruguay's President Luis Lacalle Pou and Bolivia's President Luis Arce, pose for a group photo at the 63rd Mercosur Summit, in Rio de Janeiro, Brazil, Thursday, Dec. 7, 2023. (AP Photo/Silvia Izquierdo)