using System;

public class Program

{

     static int equilibrium(int[] arr, int n){

        int leftsum=0;

       // int rightsum =0;

        int sum=0;

        for(int i=0;i<n;i++){

                             Console.WriteLine("First sum index is " + arr[i]);

​

            sum = sum + arr[i];

        }

                 Console.WriteLine(" sum  is " + sum);

​

        for(int i=0;i<n;++i){

            sum = sum -arr[i];

            if(leftsum==sum){

                return i;

            }

            leftsum += arr[i];

        }

        return -1;

    }

    public static void Main()

    {

​

    int[] arr = { -7, 1, 5, 2, -4, 3, 0 }; 

        int arr_size = arr.Length; 

        Console.Write("First equilibrium index is " + 

                           equilibrium(arr, arr_size));     }

}