Routing a Marathon Race

Example

Input

6 6 3 1 9 4 3 6 1 2 1 4 2 6 5 4 6 5 3 2

Output

17

inputFormat

Input

6 6 3 1 9 4 3 6 1 2 1 4 2 6 5 4 6 5 3 2

outputFormat

Output

17

样例

6 6
3
1
9
4
3
6
1 2
1 4
2 6
5 4
6 5
3 2

17