Clock angles X57878

It is noon and Jordi notices that the hour and minute hands are overlapping. Jordi has to leave in $m$ minutes. What angle will the two hands form when he leaves?

Input

The input consists of a single integer $m$, with $0 \leq m \leq 10080$. It is guaranteed that $m$ is a multiple of 30.

Output

Write an integer, the angle formed by the two hands in degrees.