#include<stdio.h>
int main() {
    int quatity;
    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("%.2f\n",total);
    return 0;
}