gistfile1.hh

#include <iostream>
#include <vector>
#include <sstream>
#include <cstdio>
#include <set>

using namespace std;

#define FORI for(int i = 0; i < n; ++i)
#define FORJ for(int j = 0; j < n; ++j)
#define FOR(i, n) for(int (i) = 0; (i) < (n); ++(i))

typedef long long LL;

int n;

  
class A {
public:
  int n;
  int m;
  int a[20][2];


  int check(int b[10][10]) {
    FOR(i, m) {
      if(!b[a[i][0]][a[i][1]]) {
        return 0;
      }
    }
    return 1;
  }
  void printlines(    vector<pair<int, int> >& lines) {
    FOR(i, lines.size()) {
      cout << '(' << lines[i].first << ',' << lines[i].second << ") ";
    }
    cout << endl;
  }


  void resolve() {
    int count = 0;
    int lines[200][2] = {0};
    int b[10][10] = {0};
    int t[5][2] = {{0,0}, {1, 0}, {0, 1}, {0, -1}, {-1, 0}};
    int idx = 0;
    lines[0][0] = n/2;
    lines[0][1] = n/2;

    int res = 0;
    
    while(idx >= 0) {
      //printlines(lines);
      //cerr << lines.size() << endl;
      int x = lines[idx][0];
      int y = lines[idx][1];

      b[x][y]++;
      b[n-x][n-y] = b[x][y];

      if(x == 0 or y == 0 or x == n or y == n) {
        res += check(b);
        --idx;
        b[x][y] = 0;
        b[n-x][n-y] = 0;
        continue;
      }

      // if(x < 0 or y < 0 or x > n or y > n) {
      //   lines.pop_back();
      //   continue;
      // }


      //cout << x << y << b[x][y] << endl;

      if(b[x][y] >= 5) {
        --idx;
        b[x][y] = 0;
        b[n-x][n-y] = 0;
        continue;
      }

      if(idx == 0 and b[x][y] >= 3) {
        --idx;
        b[x][y] = 0;
        b[n-x][n-y] = 0;
        continue;
      }

      int idx2 = b[x][y];
      int nx = x + t[idx2][0];
      int ny = y + t[idx2][1];

      if(nx < 0 or ny < 0 or nx > n or ny > n) continue;
      if(b[nx][ny]) continue;

      idx++;
      lines[idx][0] = nx;
      lines[idx][1] = ny;
      //cout << nx << ' ' << ny << endl;
    }
    cout << res*2 << endl;
    
  }

  
  
  void foo() {
    scanf("%d%d", &n, &m);
    n *= 2;

  
    FOR(i, m) {
      scanf("%d%d", &a[i][0], &a[i][1]);
    }

    resolve();
    return;
  }
};

int main() {
  A().foo();
}