#include<stdio.h>
struct book{
    int quantity;
    float discount;
    float total;
};
int main(){
    struct book b;
    scanf("%d",&b.quantity);
    if(b.quantity <=0 || b.quantity<=-100 ||b.quantity>=100){
        printf("Invalid input");
    }
    else if(b.quantity>=1 && b.quantity=5){
        b.discount=0.10;
    }
    else if(b.quantity>=6 && b.quantity<=10){
        b.discount=0.15;
    }
    else if(b.quantity>10){
        b.discount=0.20;
    }
    else{
        b.discount=0.00;
    }
    b.total=(100*b.quantity)*(1-b.discount);
    printf("%.2f",b.total);
    return 0;
}