// Result (from 0)
// To 0 : ---
// To 1 : No path
// To 2 : cost 23 : 2 <- 5 <- 4 <- 3 <- 0
// To 3 : cost  8 : 3 <- 0
// To 4 : cost 13 : 4 <- 3 <- 0
// To 5 : cost 20 : 5 <- 4 <- 3 <- 0