This seems like a very simple problem, but I can't see what's wrong. Please give me some test data. Yeah, I know OOP is useless:)

#include <fstream.h>

#ifdef ONLINE_JUDGE
#define in cin
#define out cout
#else
ifstream in("test.in");
ofstream out("test.out");
#endif

#define MAX 50
#define WALL 0
#define SPACE 1
#define REACH 2
#define ENTER 3

class CLabyrinth
{public:
   int a[MAX][MAX],n;
   void ReadData();
   void Fill(int x,int y);
   void Print();
   int Walls();
 };

void CLabyrinth::ReadData()
{int i,j;
 char c[MAX];
 in>>n;
 for (i=0;i<n;i++) a[0][2+i]=a[2+1][0]=a[n+1][i]=a[i][n+1]=WALL;
 a[0][0]=a[0][1]=a[1][0]=a[n+1][n+1]=a[n][n+1]=a[n+1][n]=ENTER;
 for (i=1;i<=n;i++)
  {in>>c;
   for (j=1;j<=n;j++)
    {if (c[j-1]=='.') a[i][j]=SPACE;
     if (c[j-1]=='#') a[i][j]=WALL;
     }
   }
 }

void CLabyrinth::Fill(int x,int y)
{if (a[x][y]!=SPACE) return;
 a[x][y]=REACH;
 Fill(x-1,y);Fill(x+1,y);Fill(x,y-1);Fill(x,y+1);
 }

void CLabyrinth::Print()
{int i,j;
 for (i=0;i<=n+1;i++)
  {for (j=0;j<=n+1;j++)
    {if (a[i][j]==SPACE) out<<'X';
     if (a[i][j]==WALL) out<<'#';
     if (a[i][j]==REACH) out<<'.';
     if (a[i][j]==ENTER) out<<'E';
     }
   out<<'\n';
   }
 }

int border(int a,int b)
{return(((a==REACH)&&(b==WALL))||((a==WALL)&&(b==REACH)));
 }

int CLabyrinth::Walls()
{int i,j,s=0;
 for (i=1;i<=n;i++)
   for (j=0;j<=n;j++)
     s+=border(a[i][j],a[i][j+1])+border(a[j][i],a[j+1][i]);
 return(s);
 }

void main()
{CLabyrinth Lab;
 Lab.ReadData();
 Lab.Fill(1,1);
 Lab.Fill(Lab.n,Lab.n);
 out<<9*Lab.Walls()<<'\n';
 }