#include<stdio.h>
int main()
{
    int quantity;
    float total,discountRate;
    scanf("%d", &quantity);
    if(quantity < 0){
        printf("Invalid input\n");
        return 0;
    }
    if(quantity>=1  && quantity <=5){
        discountRate = 0.10;
    }else if(quantity >=6 && quantity <=10){
        discountRate=0.15;
    }else if(quantity > 10){
        discountRate = 0.20;
    }else{
        discountRate=0.0;
    }
    total=quantity * 100 * (1 - discontRate);
    printf("%.2f\n",total);
    return 0;
}