public static string DoneOrNot(int[][] board)
  {
    for (int i = 0; i < board.Length; i++) {
      List<int> col = new List<int>();
      for (int j = 0; j < board.Length; j++) {
        var row = board[i].Distinct();
        if (row.Count() != 9)
          return "Try again!";
        col.Add(board[j][i]);
      }
      var c = col.Distinct();
      if (c.Count() != 9)
        return "Try again!";
    }
    int x = 0;
    int y = 0;
    for (int z = 0; z < 9; ++z) {
      List<int> region = new List<int>();
      for (int i = 0; i < 3; ++i) {
        for (int j = 0; j < 3; ++j) {
          region.Add(board[y + i][x + j]);
        }
      }
      var reg = region.Distinct();
      if (reg.Count() != 9)
        return "Try again!";

      x+=3;
      if(x>6) {
        y += 3;
        x = 0;
      }
    }
    return "Finished!";
  }