Mubashir needs your help to find out trailing zeros after calculating factorial of a given number.

Create a function which takes a number n and calculates the number of trailing zeros in factorial of the given number.

n! = 1 * 2 * 3 * ... * n

Examples

trailing_zeros(0) ➞ 0
# 0! = 1
# No trailing zero.

trailing_zeros(6) ➞ 1
# 6! = 720
# 1 trailing zero.

trailing_zeros(1000) ➞ 249
# 1000! has 249 trailing zeros.

Notes

Hint: No need to calculate the factorial (because it won't help). Find another way to find the number of zeros.