public static void Main()
var weight = int.Parse(Console.ReadLine());
var lenght = int.Parse(Console.ReadLine());
long cakeSize = weight * lenght;
string current = Console.ReadLine();
cakeSize -= int.Parse(current);
Console.WriteLine("No more cake left! You need {0} pieces more.", Math.Abs(cakeSize));
Console.WriteLine("{0} pieces are left.", cakeSize);