Code Submission Evaluation System Login

CSES Problem Set

Trailing Zeros


Task | Statistics


CSES - Trailing ZerosCSES - Trailing Zeros

Time limit:1.00 s Memory limit:512 MB

Your task is to calculate the number of trailing zeros in the factorial $n!$.

For example, $20!=2432902008176640000$ and it has $4$ trailing zeros.

Input

The only input line has an integer $n$.

Output

Print the number of trailing zeros in $n!$.

Constraints
Example

Input:
20

Output:
4