import java.util.Scanner;

public class _1506 {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        int n, k, j, i;

        n = s.nextInt();
        k = s.nextInt();

        k = (n + k - 1) / k;
        int[] a = new int[n];
        for (i = 0; i < n; i++) {
            a[i] = s.nextInt();
        }

        for (j = 0; j < k; System.out.println(""), j++)
            for (i = j; i < n; i += k) {
                System.out.print(" " + a[i]);
            }
    }
}