#include<sytdio.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*(1-discountRate);
    printf("%.2f\n",total);
    return 0;
    }