031. 2001: A Space Odyssey
time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output

While listening to an orchestra fail to play the music from 2001: A Space Odyssey, you wonder what the lowest positive number (other than one) that divides 2001 is. It turns out to be 3 (2001 = 3 * 667). Write a program to find this value for any composite number $$$n$$$.

Input

The only line of input contains a single positive composite (not prime) integer $$$n$$$, greater than one: the number used in your calculations.

Output

Output a single positive integer k: the smallest positive number (other than one) that divides $$$n$$$.

Example
Input
2001
Output
3