class RB {
  final static int N = 100;
  final static int T = 10;
  final static double C = 0.5;
  final static int root = 0;

  static char m[][] = new char[N][N];

  static void rand_fill(char c, int n)
  {
    while (n-- > 0) {
      int i, j;
      do {
        i = BSDRand.rand(N);
        j = BSDRand.rand(N);
      } while (m[j][i] != ' ');
      m[j][i] = c;
    }
  }

  static void zero_array()
  {
    for (int i = 0; i < N; i++)
      for (int j = 0; j < N; j++)
        m[j][i] = ' ';
  }

  static void init_array()
  {
    zero_array();
    rand_fill('r', N * N / 4);
    rand_fill('b', N * N / 4);
  }

  static void print_array()
  {
    int i, j;
    char[] line = new char[N];
    
    for (j = 0; j < N; j++) {
      for (i = 0; i < N; i++) {
        line[i] = m[j][i];
      }
      System.out.println(line);
    }
  }

  static int count_cells(int c, int ti, int tj)
  {
    int cnt = 0;
    
    ti *= T;
    tj *= T;
    
    for (int i = 0; i < T; i++)
      for (int j = 0; j < T; j++)
        if (m[tj + j][ti + i] == c)
          cnt++;
    
    return cnt;
  }

  public static void main(String[] args)
  {
    boolean show = false, red_moved, blue_moved;
    int cnt = 0, n;

    n = Integer.valueOf(args[0]);

    BSDRand.srand(n);
    init_array();
    show = (args.length > 1);

    if (show)
      System.out.println(N);

    do {
      if (show)
        print_array();

      /* Check regions: */
      {
        boolean done = false;

        for (int k = 0; k < (N/T)*(N/T); k++) {
          int i = k % (N/T);
          int j = k / (N/T);
          
          int rc = count_cells('r', i, j);
          int bc = count_cells('b', i, j);
          
          if ((rc > (T * T * C))
              || (bc > (T * T * C)))
            done = true;
        }

        if (done)
          break;
      }

      red_moved = false;

      for (int j = 0; j < N; j++) {
        boolean left_white = (m[j][0] == ' ');
        int i;
        for (i = 0; i < N-1; i++) {
          if ((m[j][i] == 'r') && (m[j][i+1] == ' ')) {
            m[j][i] = ' ';
            m[j][i+1] = 'r';
            red_moved = true;
            i++; /* don't move again */
          }
        }
        if (i < N) {
          if ((m[j][N-1] == 'r') && left_white) {
            m[j][N-1] = ' ';
            m[j][0] = 'r';
            red_moved = true;
          }
        }
      }

      blue_moved = false;

      for (int i = 0; i < N; i++) {
        boolean top_white = (m[0][i] == ' ');
        int j;
        for (j = 0; j < N-1; j++) {
          if ((m[j][i] == 'b') && (m[j+1][i] == ' ')) {
            m[j][i] = ' ';
            m[j+1][i] = 'b';
            blue_moved = true;
            j++; /* don't move again */
          }
        }
        if (j < N) {
          if ((m[N-1][i] == 'b') && top_white) {
            m[N-1][i] = ' ';
            m[0][i] = 'b';
            blue_moved = true;
          }
        }
      }

      cnt++;
    } while (red_moved || blue_moved);

    if (!show)
      System.out.println(cnt);
  }
}