#include <bits/stdc++.h>
using namespace std;

struct moves
  {
    int x;
    int y;
  };
queue <moves> MQue;

bool Marked[8][8];

void StartProcess()
  {
    for (int i=0; i<8; i++)
      for (int j=0; j<8; j++) Marked[i][j]=false;
    int n;
    cin >> n;
    for (int i=0; i<n; i++)
      {
        int x,y;
        cin >> x >> y;
        Marked[x-1][y-1]=true;
      }
  }

bool Found(int &x, int &y)
  {
    for (int i=0; i<8; i++)
      for (int j=0; j<8; j++)
        if (not Marked[i][j])
          { x=i; y=j; return true;};
    return false;
  }

void PutAll(moves CurrMove)
  {
   int steps[4][2] = {{0,-1},{0,1},{-1,0},{1,0}};
   for (int i=0; i<4; i++)
     {
       moves Cur;
       Cur.x=CurrMove.x+steps[i][0];
       Cur.y=CurrMove.y+steps[i][1];
       if ((Cur.x>=0) && (Cur.x<8) &&
           (Cur.y>=0) && (Cur.y<8) &&
           (not Marked[Cur.x][Cur.y]))
          {MQue.push(Cur); Marked[Cur.x][Cur.y]=true;};
     }
  }

int main()
{
 freopen("input.txt","r",stdin);
 freopen("output.txt","w",stdout);
 StartProcess();
 int PieceNumber=0,x,y;
 while (Found(x,y))
   {
     PieceNumber++;
     moves StartMove; StartMove.x=x; StartMove.y=y;
     MQue.push(StartMove); Marked[x][y]=true;
     while (not MQue.empty())
       {
         moves CurrMove=MQue.front(); MQue.pop();
         PutAll(CurrMove);
       }
   }
 cout << PieceNumber; }

#include <bits/stdc++.h>using namespace std;

queue <int> X,Y;   // Две очереди по одному числу

bool Marked[8][8];

void StartProcess()
  {
    for (int i=0; i<8; i++)
      for (int j=0; j<8; j++) Marked[i][j]=false;
    int n;
    cin >> n;
    for (int i=0; i<n; i++)
      {
        int x,y;
        cin >> x >> y;
        Marked[x-1][y-1]=true;
      }
  }

bool Found(int &x, int &y)
  {
    for (int i=0; i<8; i++)
      for (int j=0; j<8; j++)
        if (not Marked[i][j])
          { x=i; y=j; return true;};
    return false;
  }

void PutAll(int x, int y)
  {
   int steps[4][2] = {{0,-1},{0,1},{-1,0},{1,0}};
   for (int i=0; i<4; i++)
     {
       int Cx=x+steps[i][0];
       int Cy=y+steps[i][1];
       if ((Cx>=0) && (Cx<8) &&
           (Cy>=0) && (Cy<8) &&
           (not Marked[Cx][Cy]))
          {X.push(Cx); Y.push(Cy); Marked[Cx][Cy]=true;};
     }
  }

int main()
{
 freopen("input.txt","r",stdin);
 freopen("output.txt","w",stdout);
 StartProcess();
 int PieceNumber=0,x,y;
 while (Found(x,y))
   {
     PieceNumber++;
     X.push(x); Y.push(y); Marked[x][y]=true;
     while (not X.empty())
       {
         x=X.front(); X.pop();
         y=Y.front(); Y.pop();
         PutAll(x,y);
       }
   }
 cout << PieceNumber; }