#include<stdio.h>
int main()
{
    int quantity;
    scanf("%d",&quantity);
    if(quantity<0)
    {
        printf("Invalid input");
        return 0;
    }
    float cost = quantity*100;
    float discount=0;
    if(quantity>=1 && quantity<=5)
    discount =0.10;
    else if(quantity>=6 && quantity<=10)
    discount =0.15;
    else if(quantity>10)
    discount=0.20;
    float total=cost-(coast*discount);
    printf("%.2f",total);
    return 0;
    }