using System;

public class Program

{

    public static void Main()

    {

        var car1 = new Car(){ Fuel = 10 };

        var car2 = new Car(){ Fuel = 10 };

        car1.Charge(15);

        car2.Charge(21);

        Console.WriteLine(Car.GetCarInfo(car1));

        Console.WriteLine(Car.GetCarInfo(car2));

    }

    public class Car{

        public int Fuel {get;set;}

        public void Charge(int count){

            this.Fuel+=count;

        }

        public static string GetCarInfo(Car c){

            return "Car fuel is: " + c.Fuel;

        }

    }

}