#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<stack>
#include<vector>
using namespace std;
int main()
{
int a,b,w;
double hours,minutes,ans;
string k;
while(scanf("%d:%d",&a,&b))
{
if(a==0&&b==0) return 0;
hours=(double)a*30+0.5*(double)b;
minutes=b*6;
if(hours>minutes) ans=hours-minutes;
else ans=minutes-hours;
if(ans>180) ans=360-ans;
printf("%.3f\n",ans);
}
}