#include <bits/stdc++.h>
int main() {
  int i, j, N, M;
  scanf("%d", &N);
  M = N * N;
  for (i = 1; i <= N * N / 2;) {
    for (j = 0; j < N / 2; ++j, ++i, --M) {
      printf("%d %d ", i, M);
    }
    printf("\n");
  }
  return 0;
}
