怎么错了？
大家看看。。。

var
  xx,yy,m,n,i,j,tot,code:integer;
  house:array[0..21,0..21]of char;
  went:array[0..21,0..21]of boolean;
  st,c:string;a:char;men:boolean;
procedure search(x,y:integer);
begin
  if not went[x,y] then begin
    went[x,y]:=true;
    inc(tot);
    if house[x,y-1]<>'#' then search(x,y-1);
    if house[x,y+1]<>'#' then search(x,y+1);
    if house[x-1,y]<>'#' then search(x-1,y);
    if house[x+1,y]<>'#' then search(x+1,y);
  end;
end;
begin
  readln(m,n);
  while not((m=0)and(n=0)) do begin
    fillchar(house,sizeof(house),' ');
    fillchar(went,sizeof(went),false);
    tot:=0;men:=false;
    for i:= 1 to n do begin
      for j:= 1 to m do
        read(house[i,j]);
      if not men then
        for j:= 1 to m do
          if house[i,j]='@' then begin
            xx:=i;yy:=j;
            men:=true;
            break;
          end;
      read(a);read(a);
    end;
    for i:= 0 to m+1 do begin
      house[0,i]:='#';
      house[n+1,i]:='#';
    end;
    for i:= 0 to n+1 do begin
      house[i,0]:='#';
      house[i,m+1]:='#';
    end;
    search(xx,yy);
    writeln(tot);
    readln(m,n);
  end;
end.