#include<stdio.h>
struct books
{
    int n;
};
int main()
{
    struct books d;
    scanf("%d",&d.n);
    if(d.n<0)
    {
        printf("Invalid input");
    }
    else if(d.n<5&&d.n>0) 
    {
        float a=((d.n*100)*(1.0-0.10))
        printf ("%.2f",a);
    }
    else if(d.n<11&&d.n>5)
    {
        float b=((d.n*100)*(1.0-0.15))
        printf("%.2f",b);
    }
    else if(d.n>11)
    {
        float c=((d.n*100)*(1.0-0.20))
        printf("%.2f",c);
    }
    else
    {
        printf("Invalid input");
    }
    return 0;
}