#include<stdio.h>
int main(){
    int quatity;
    float total,discountRate;
    scanf("%d", &quatity);
    if (quatity < 0){
        printf("Invaild input\n");
        return 0;
    }
    if (quatity >= 1 && quatity <= 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 - discountRate);
    printf("%.2f\n",total);
    return 0;
}