#include<iostream>
using namespace std;;

double water_usage(double warm, double cold, double persons)
{
double warm_cold_water_price = 8.20;
double heat_up_water = 15.30;
double person_price = 5;
double cold_price = warm_cold_water_price*cold+(person_price*persons);
double warm_price = (warm_cold_water_price+heat_up_water)*warm+(person_price*persons);
double full_price = cold_price + warm_price;
return full_price;
}

int main()
{
    cout << water_usage(10, 23, 2);
    return 0;
}