**Solution**

**Factorial Trailing Zeroes** https://leetcode.com/problems/factorial-trailing-zeroes/?tab=Description

**Algorithm**

- 2 * 5 gives a trailing zero
- We have plenty of 2
- Just need to find 5
- 5,10,15,20,25,...
- But 25 gives 2 5s, 75! will have 25, 50, 75, three more
- This will give us the algorithm

```
class Solution(object):
def trailingZeroes(self, n):
"""
:type n: int
:rtype: int
"""
count = 0
start = 5
while start <= n:
count = count + n//start
start = start*5
return count
```