1. Stuck Numbers

import java.util.Scanner;


public class _01_Problem1 {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int count = Integer.parseInt(sc.nextLine());
        String[] numbers = sc.nextLine().split(" ");
        boolean isAny = false;

        for(int i = 0; i < numbers.length; i++) {
            for (int j = 0; j < numbers.length; j++) {
                if (i == j)
                    continue;
                else {
                    for (int m = 0; m < numbers.length; m++) {
                        if(m == i || m == j)
                            continue;
                        else {
                            for (int k = 0; k < numbers.length; k++) {
                                if (k == m || k == j || k == i)
                                    continue;
                                else {
                                    String str1 = numbers[i] + numbers[j];
                                    String str2 = numbers[k] + numbers[m];
                                    if(str1.equals(str2)) {
                                        System.out.println(numbers[i] + "|" + numbers[j] + "==" + numbers[k] + "|" + numbers[m]);
                                        isAny = true;
                                    }
                                }
                            }
                        }
                    }
                }
            }
        }

        if(!isAny)
            System.out.println("No");
    }

}