 Complete the following phrase:  At the 1972 Summer Olympics in Munich, Česiūnas won gold in the C-2 1000 m with Yuri Lobanov. He also won six canoe sprint world championship medals with four golds C-2 1000 m: 1974, C-2 10000 m: 1973, 1974, 1975, one silver C-2 1000 m: 1973, and one bronze C-1 1000 m: 