I'm getting stack limit exceeded on one of the test cases which is a 100x100 matrix of all 1's.

Anyone have an idea what is wrong with my implementation?

```
class Solution(object):
def findCircleNum(self, A):
count = 0
def dfs(row, column):
if row < 0 or column >= len(A[0]) or row >= len(A) or column < 0:
return
if A[row][column] == 0:
return
A[row][column] = 0
for i in range(row-1, row+2):
if i >= 0 and i<len(A) and A[i][column] == 1:
dfs(i, column)
for i in range(column-1, column+2):
if i >= 0 and i<len(A[0]) and A[row][i] == 1:
dfs(row, i)
for row in range(len(A)):
for column in range(len(A[0])):
if A[row][column] == 1:
dfs(row, column)
count += 1
return count
```