#include<bits/stdc++.h>

int main(){
    int a, b;
    scanf("%d %d", &a, &b);
    double x = a%12 * 30 + b/2.0;
    double y = b*6;
    if(x<y) x += 360;

    printf("%d\n", (int)(120*(x-y)/11));
    return 0;
}