/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		int[] nums = {2, 7, 11, 15};
		ArrayList<Integer> index = new ArrayList<Integer>();
        int t = 26;
 
        for(int i=0 ; i < nums.length-1 ; i++){
        	for(int j=i+1 ; j < nums.length ; j++){
        		if(nums[i] + nums[j] == t){
        			index.add(i);
        			index.add(j);
        		}
        	}
        }
        System.out.println(index);
	}
}

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