The purpose of this problem is to calculate the size of overlapping area of every operation, the area is a rectangular area, and the length of the rectangular is the minimal number of every operation's first number, the width is the minimal number of every operation's second number.

```
class Solution(object):
def maxCount(self, m, n, ops):
"""
:type m: int
:type n: int
:type ops: List[List[int]]
:rtype: int
"""
if not ops:
return m*n
x, y = 1e9, 1e9
for op in ops:
if op[0] < x:
x = op[0]
if op[1] < y:
y = op[1]
return x*y
```