#include<stdio.h>
struct Order {
    int quantity;
    float price_per_book;
    union {
        float discountRate;
        int disocuntpercent;
    } disc;
    float total_cost;
};
int main() {
    struct Order order;
    order.price_per_book = 100.0f;
    scanf("%d",&order.quanity);
    if(order.quantity<0) {
        printf("Invalid input");
        return 0;
    }
    if(order.quantity>=1 && order.quantity<=5) {
        order.disc.discountRate = 0,10f;
    }
    else if(order.quantity>=6 && order.quantity<=10)
    {
        order.disc.discountRate=0.15;
    }
    elde if(order.quantity >10) {
        order,disc,discountRate =0.20f;
    }
    else {
        order.disc.discoumtRate =0.0f;
        }
        float.disc.discountRate * order.price_per_book;
        order.total_cost = gross * (1.0f - order.disc.discountRate);
        return 0;
}