TAXI - TAXI
Input
6 0 4 2 3 5 4 4 4 0 7 5 2 3 1 3 2 0 1 2 1 9 2 3 5 0 9 8 3 2 1 4 6 0 9 1 9 8 1 4 2 0 8 1 2 3 2 5 4 0
Output
13
Nguồn: ĐPT '1920