#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 if (quantity > 10){
        discountRate = 0.20;
    } else {
        discountRate = 0.0;
    }
    
    total = quantity * 100 * (1 - discountRate);
    
    printf("%.2f\n", total);
    
    return 0;
}