Problem Statement

You are given a positive integer $N$. Find the largest positive integer $M$ satisfying the following condition. If $M$ can be arbitrarily large, output INF.

• All cells of a rectangle consisting of $N×M$ cells can be painted white or black so that there exists no tuple of positive integers $(x_1,x_2,y_1,y_2)$ satisfying the following conditions.
• $1 \le x_1 < x_2 \le N$
• $1 \le y_1 < y_2 \le M$
• Denoting the cell in the $i$-th row from the top and the $j$-th column from the left by $(i,j)$, the cells $(x_1,y_1),(x_1,y_2),(x_2,y_1),(x_2,y_2)$ are all the same color.

Input

$N$

• All inputs are positive integers.
• $2 \le N \le 10^{18}$

Output

Output the largest positive integer $M$ satisfying the condition. If $M$ can be arbitrarily large, output INF.

Sample

5

4