public class n1 {

    public static void main(String[] args) {
        //              0       1       2       3           4           5
        int[][] arr = new int[20][20];
        for (int i = 0; i < arr.length; i++) {
            for (int j = 0; j < arr[i].length; j++) {
                arr[i][j] = i-j;
            }
        }
        toStringArr(arr);

        for (int i = 0; i < arr.length; i++) {
            int temp = arr[0][i];
            arr[0][i] = arr[1][i];
            arr[1][i] = temp;
        }
        toStringArr(arr);
    }
    public static void toStringArr(int[][] arr) {
        String str = "";
        for (int i = 0; i < arr.length; i++) {
            for (int j = 0; j < arr[i].length; j++) {
                str += arr[i][j];
                str += " ";
            }
            str += "\n";
        }
        System.out.println(str);
    }
}