#include <stdio.h>
int main () {
    int quantity;
    float total, descountRate;
    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;
    }