public class Test
{
    public static void main(String[] args)
    {
        int sum = 10;

        System.out.println(sum(1, 2));
        System.out.println(sum(1, 2, 3));
        System.out.println(sum(1, 2, 3, 4));
    }

    public static int sum(int a, int b) { return a + b; }
    public static int sum(int a, int b, int c) { return a + b + c; }
    public static int sum(int a, int b, int c, int d) { return a + b + c + d; }

}