Can anyone let me know what the complexity of this problem? I got TLE with O(m*n*len(strs)). Here's my code:

```
class Solution(object):
def findMaxForm(self, strs, m, n):
"""
:type strs: List[str]
:type m: int
:type n: int
:rtype: int
"""
k = len(strs)
if k == 0: return 0
a = [0]*(k+1)
b = [0]*(k+1)
for i in range(k):
a[i+1] = strs[i].count('0')
b[i+1] = strs[i].count('1')
f = [[0]*(n+1) for i in range(m+1)]
for t in range(1, k+1):
for i in range(m, -1, -1):
for j in range(n, -1, -1):
if i >= a[t] and j >= b[t] and f[i][j] < f[i-a[t]][j-b[t]] + 1:
f[i][j] = f[i-a[t]][j-b[t]] + 1
return f[m][n]
```