#include <bits/stdc++.h>
using namespace std;
int main(){
  int k; cin >> k;
  int n = 2 * ((k + 3)/4);
	if(k == 1){
		cout << 1 << endl;
		cout << 1 << endl;
		return 0;
	}
  cout << n << endl;
	vector<vector<int> > res(n, vector<int>(n, 0));
	int mx = 0;
  for(int i = 0; i < n; i++){
    for(int j = 0; j < n; j++){
      int c = (i + j)%n;
      if(i&1) c += n;
	res[i][j] = c + 1;
    	mx = max(mx, c + 1);
	}
  }
	while(mx != k){
		for(int i = 0; i < n; i++){
			for(int j = 0; j < n; j++){
				if(res[i][j] == mx) res[i][j] -= n;
			}
		}
		mx--;
	}
	for(int i = 0; i < n; i++){
		for(int j = 0; j < n; j++){
			cout << res[i][j] << " \n"[j+1 == n];
		}
	}
  return 0;
}

### Prompt

In cpp, your task is to solve the following problem:

For an n \times n grid, let (r, c) denote the square at the (r+1)-th row from the top and the (c+1)-th column from the left. A good coloring of this grid using K colors is a coloring that satisfies the following:

* Each square is painted in one of the K colors.
* Each of the K colors is used for some squares.
* Let us number the K colors 1, 2, ..., K. For any colors i and j (1 \leq i \leq K, 1 \leq j \leq K), every square in Color i has the same number of adjacent squares in Color j. Here, the squares adjacent to square (r, c) are ((r-1)\; mod\; n, c), ((r+1)\; mod\; n, c), (r, (c-1)\; mod\; n) and (r, (c+1)\; mod\; n) (if the same square appears multiple times among these four, the square is counted that number of times).



Given K, choose n between 1 and 500 (inclusive) freely and construct a good coloring of an n \times n grid using K colors. It can be proved that this is always possible under the constraints of this problem,

Constraints

* 1 \leq K \leq 1000

Input

Input is given from Standard Input in the following format:


K


Output

Output should be in the following format:


n
c_{0,0} c_{0,1} ... c_{0,n-1}
c_{1,0} c_{1,1} ... c_{1,n-1}
:
c_{n-1,0} c_{n-1,1} ... c_{n-1,n-1}


n should represent the size of the grid, and 1 \leq n \leq 500 must hold. c_{r,c} should be an integer such that 1 \leq c_{r,c} \leq K and represent the color for the square (r, c).

Examples

Input

2


Output

3
1 1 1
1 1 1
2 2 2


Input

9


Output

3
1 2 3
4 5 6
7 8 9

### Response

```cpp
#include <bits/stdc++.h>
using namespace std;
int main(){
  int k; cin >> k;
  int n = 2 * ((k + 3)/4);
	if(k == 1){
		cout << 1 << endl;
		cout << 1 << endl;
		return 0;
	}
  cout << n << endl;
	vector<vector<int> > res(n, vector<int>(n, 0));
	int mx = 0;
  for(int i = 0; i < n; i++){
    for(int j = 0; j < n; j++){
      int c = (i + j)%n;
      if(i&1) c += n;
	res[i][j] = c + 1;
    	mx = max(mx, c + 1);
	}
  }
	while(mx != k){
		for(int i = 0; i < n; i++){
			for(int j = 0; j < n; j++){
				if(res[i][j] == mx) res[i][j] -= n;
			}
		}
		mx--;
	}
	for(int i = 0; i < n; i++){
		for(int j = 0; j < n; j++){
			cout << res[i][j] << " \n"[j+1 == n];
		}
	}
  return 0;
}

```