#include<stdio.h>
int main(){
    int  quantity;
    scanf("%d",&quantity);
    if (quantity < 0) {
        printf("Invalid input");
        return 0;
    }
    float priceperBook = 100;
    float discount = 0.0;
    
    if (quantity >= 1 && quantity <= 5) {
        discount = 0.10;
    }
    else if (quantity >= 6 &&  quantity <=10){
        discount = 0.15;
    }
    float total =  quantity * pricePerBook;
    float finalCost = total - (total * discount);
    printf("%.2f", finalCost);
    return 0;
}