#include<stdio.h>
struct book
{
    int n;
    
};
int main()
{
    struct book;
    scanf("%d",&a.n);
if(a.n<0)
{
    printf("Invalid input");
}
else if(a.n<6 && a.n>0)
{
    float s=((a.n*100)*(1.0-0.10));
    printf("%.2f",s);
}
else if(a.n<11 && a.n>5)
{
    float b=((a.n*100)*(1.0-0.15));
    printf("%.2f",b);
}
else if(a.n>10)
{
    float c=((a.n*100)*(1.0-0.20));
    printf("%.2f",c);
}
else {
    printf("Invalid input");
}
return 0;
}