#include<stdio.h>

struct book
{
    int n;
};
int main()
{
    struct book a;
    scanf("%d",&a.n);
    if(a.n<0)
    {
        printf("Invalid input");
    }
    else if(a.n<6&&a.n>0)
    {
        float a=((a.n*100)*(1.0-0.10));
        printf("%.2f",a);
    }
    else if(a.n<||&&a.n>5)
    {
        float b=((a.n*100)*(1.0-0.15));
        printf("%.2f",b);
    }
    else if(a.n>||)
    {
        float c=((a.n*100)*(1.0-0.20));
        printf("%.2f",c);
    }
    else
    {
        printf("Invaild input");
    }
}