#include<stdio.h>
int main()
{
    int H,M;
    char ch;
    float a,b,c,d,e,f;
    while(scanf("%d%c%d",&H,&ch,&M)!=EOF)
    {
        if(H==0 && M==0)
        break;
        a=H*60;
        b=a+M;
        c=b*.5;
        d=M*6;
        if(c>d)
        {
            e=c-d;
        }
        else
        {
            e=d-c;
        }
        if(e>180)
        {
            f=360-e;
            printf("%.3f\n",f);
        }
        else if(e<=180)
        {
            printf("%.3f\n",e);
        }
    }
    return 0;
}