static void Main(string[] args)
{
    Console.WriteLine("Enter number:");
	int num1=Convert.ToInt32(Console.ReadLine());
	Console.WriteLine("Enter number:");
	int num2 = Convert.ToInt32(Console.ReadLine());
	Console.WriteLine(sum(num1, num2));
	Console.WriteLine(sub(num1, num2));
	Console.WriteLine(mul(num1, num2));
    Console.WriteLine(div(num1, num2));
	Console.ReadKey();
}

public static int sum(int num1, int num2)
{
	return num1 + num2;
}
public static int sub(int num1, int num2)
{
	return num1 - num2;
}
public static int mul(int num1, int num2)
{
	return num1 * num2;
}
public static int div(int num1, int num2)
{
	return num1 / num2;
}