```
class Solution(object):
def trailingZeroes(self, n):
"""
:type n: int
:rtype: int
"""
if n<5:
return 0
else:
sums = 0
i = 1
#only 5, 25 ,125...can increase the 0 numbers.
while n//(5*i) >=1:
sums += n//(5*i)
i*=5
return sums
```