#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 *(i-discountrate);
    printf("%.2f\n",total);
    return 0;
}