Midpoint

Example

Input

2 2 3 0 0 2 0 0 0 0 2 0 0 1 1 1 1

Output

3

inputFormat

Input

2 2 3 0 0 2 0 0 0 0 2 0 0 1 1 1 1

outputFormat

Output

3

样例

2 2 3
0 0
2 0
0 0
0 2
0 0
1 1
1 1

3