```
class Solution(object):
def leastBricks(self, wall):
"""
:type wall: List[List[int]]
:rtype: int
"""
map = {}
for i in range(len(wall)):
sum = 0
for j in range(0, len(wall[i])-1):
sum += wall[i][j]
if map.get(sum) is not None:
map[sum] += 1
else:
map[sum] = 1
return len(wall) - max(map.values()) if map.values() else len(wall)
```