#include<stdio.h>
int main() {
    int quantity;
    float totalcost,discount= 0.0;
    scanf("%d",&quantity);
    if(quantity<0){
        printf("Invalid input\n");
        return 0;
    }
    totalcost=quantity * 100.0;
    if(quantity>= 1 && quantity<= 5){
        discount =0.10;
    }else if(quantity>10){
        discount=0.20;
    }
    toatalcost = total*(1-discount);
    printf("%.2f\n",totalcost);
    return 0;
}