#include<stdio.h>
int main()
{
 int u;
 scanf("%d", &u);
 if (u<0)
 {
     printf("Invalid input\n");
 }
 else
 {
     double b=0.0;
     if(u>200)
     {
         b+=(u-200)*0.20;
         u=200;
     }
     if(u>100)
     {
         b+=(u-100)*0.15;
         u=100;
     }
     b+=u*0.10;
     printf("%.2f\n",b)
 }
}