#include<stdio.h>
int main () {
    int quantity;
    float total, discounRate;
    
    scanf("%d", &quantity);
    
    if (quantity < 0) {
        printf("Invalid input\n");
        return 0;
    }(quantity >= 1 && quantity <= 5) {
        discounRate = 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;
}