#include<stdio.h>
int main()
{
    int quantity;
    scanf("%d", &quantity);
    if(quantity<0)
    {
        printf("Invalid input");
        return 0;
    }
    float pricePerBook=100.0;
    float totalcost=quantity*pricePerBook;
    float discount =0.0;
    if(quantity>=1 && quantity<=5)
    {
        discount=0.10;
    }
    else if (quantity>=6 && quantity <=10)
    {
        discount =0.15;
    }
    else if(quantity >10)
    {
        discount=0.20;
    }
    totalcost = totalCost - (totalCost*discount);
    printf("%.2f",totalcost);
    return 0;
}