class mymath
{
private mymath()
{ }
public static int sum(int a, int b)
{
return a + b;
}
public static int sub(int a, int b)
{
return a - b;
}
public static int mul(int a, int b)
{
return a * b;
}
public static int div(int a, int b)
{
return a / b;
}
}
class Program
{
static void Main(string[] args)
{
Console.WriteLine(mymath.sum(23, 78));
Console.ReadKey();
}
}