#include<bits/stdc++.h>
using namespace std;
int n, T, ans[1010][1010], cnt, dir[4][2] = {{1, 0}, {-1, 0}, {0, -1}, {0, 1}};
char mp[1010][1010];
bool vis[1010][1010];
queue<pair<int, int> > q;
int main(){
	cin >> n >> T;
	for(register int i = 1;i <= n;i++){
		for(register int j = 1;j <= n;j++){
			//char a;
			//scanf("%c", &a);
			//mp[i][j] = a;
  			cin >> mp[i][j];
		}
	}
	while(T--){
		int a, b;
		scanf("%d%d", &a, &b);
		if(ans[a][b] > 0){
			cout << ans[a][b] << endl;
			continue;
		}
		memset(vis, 0, sizeof vis);
		while(!q.empty()){
			q.pop();
		}
		queue<pair<int, int> > t;
		q.push(make_pair(a, b));
		t.push(make_pair(a, b));
		vis[a][b] = 1;
		cnt = 1; 
		while(!q.empty()){
			int x = q.front().first, y = q.front().second;
			q.pop();
			for(int i = 0;i < 4;i++){
				int xx = x + dir[i][0], yy = y + dir[i][1];
				if(!vis[xx][yy] && xx >= 1 &&  yy >= 1 && xx <= n && yy <= n && mp[xx][yy] != mp[x][y]){
					cnt++;
					q.push(make_pair(xx, yy));
					t.push(make_pair(xx, yy));
					vis[xx][yy] = 1;
				}
			}
		}
		while(!t.empty()){
			int x = t.front().first, y = t.front().second;
			ans[x][y] = cnt;
			t.pop();
		}
		cout << ans[a][b] << endl;
	}
} 

结果无误，但是TLE了第二个点