#include<stdio.h>
int main()
{
    int n;
    float total;
    scanf("%d", &n);
    if(n < 1)   ;
    {
        printf("Invalid input");
    }
    else if (n <= 5)
    {
        total = n * 100 * 0.9;
        printf("%.2f", total);
    }
    else if (n <=10)
    {
        total = n * 100 * 0.85;
        printf("%.2f", total);
        
    }
    else
    {
        total = n * 100 * 0.8;
        printf("%.2f", total);
    }
    return 0;
}