尝试一下以下三组 hack：

#1

Input

2 2 1
1000000000 1000000000
1000000000 1000000000
1 2 1 2

Output

1000000000000000000

#2

Input

2 2 1
1 -1 
-3 -2 
1 1 1 2

Output

-3

#3

Input

2 2 1
-1000000000 1000000000
-1000000000 1000000000
1 2 1 2

Output

-1000000000000000000