using System;

public class Program

{

    public static void Main()

    {

        var arr = new[]{1,3,12,4,5};

        int goal = 7;

        int sum = 0;

        int p1 = 0;

        int p2=0;

        for(int i=0;i<arr.Length; i++)

        {

            for(int j=i+1;j<arr.Length-(i+1); j++)

            {

                sum = arr[i] + arr[j];

                if(sum==goal)

                {

                    p1 = i;

                    p2 = j;

                    break;

                }

                Console.WriteLine($"{j} {arr[j]}");

            }

            if(sum == goal)

                break;

        }

        Console.WriteLine($"{sum} {p1}:{p2}");

    }

}