BFS

ll n,m;
const ll Max1=1005;
char t[Max1][Max1];
ll pd[Max1][Max1];
ll dx[4]={0,0,1,-1},dy[4]={1,-1,0,0};

void bfs(ll x,ll y)
{
  ll ans=1;
  vector<pair<ll,ll>>jyh;
  queue<pair<ll,ll>>dl;
  dl.push(make_pair(x,y));
  jyh.push_back(make_pair(x,y));
  pd[x][y]=1;
  while(!(dl.empty()))
  {
  	ll x1,y1;
  	x1=dl.front().first,y1=dl.front().second;
  	dl.pop();
  	for(int i=0;i<4;i++)
    {
      if(((x1+dx[i]>=1&&x1+dx[i]<=n)&&(y1+dy[i]>=1&&y1+dy[i]<=n))&&t[x1][y1]!=t[x1+dx[i]][y1+dy[i]]&&pd[x1+dx[i]][y1+dy[i]]==0)
      {
        ans++;
        dl.push(make_pair(x1+dx[i],y1+dy[i]));
        jyh.push_back(make_pair(x1+dx[i],y1+dy[i]));
        pd[x1+dx[i]][y1+dy[i]]=1;
      }
    }
  }
  for(auto i:jyh)
  	pd[i.first][i.second]=ans;
  return ;
}
int main() 
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cin>>n>>m;
    for(int i=1;i<=n;++i)
      for(int j=1;j<=n;++j)
        cin>>t[i][j];
    while(m--)
    {
      ll x,y;
      cin>>x>>y;
      if(pd[x][y]==0)
        bfs(x,y);
      cout<<pd[x][y]<<'\n';
    }
    return 0;
}