#include<iostream>#include<stdlib.h>#include<stdio.h>#include<math.h>using namespace std;int main(){int a;double s=0;cin>>a; if (a<=240) s=0.4883*a;else if (a<=400) s=0.4883*240+0.5383*(a-240);else s=0.4883*240+0.5383*160+0.7883*(a-400);printf("%.2lf",s); return 0;