public class Main {
    static String[] A = new String[] {"1", "2", "3", "4"};
  
    private static String toString(String[] s) {
        String result = "";
        for (int k=0; k < s.length; k++) {
            result += s[k];
        }
        return result;
    }

    private static void swap(int i, int j) {
        String tmp = A[i];
        A[i] = A[j];
        A[j] = tmp;
    }

    public static void main(String[] args) {
        int i, j;
 
        System.out.println(toString(A));

        for (i = 0; i < A.length; i++ ) {
            for (j = i+1; j < A.length; j++) {
                swap(i, j);
                System.out.println(toString(A));
            }
        }
    }
}