#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- discountRate);
    printf("%.2\n",total);
    return 0;
}