已老实，求放过

#include<bits/stdc++.h>

#define IOS; ios :: sync_with_stdio(false);

using namespace std;	

const int N = 1e3 + 010;

struct node {
	int x, y;
};

int ans = 1;
int n, m;
char a[N][N];
int dx[] = {1, 0, -1, 0};
int dy[] = {0, 1, 0, -1};
int vis[N][N];

void bfs (int xx, int yy) {
	queue<node> q;
	q.push ({xx, yy});
	vis[xx][yy] = 1;
	while (!q.empty ()) {
		auto t = q.front ();
		q.pop();
		int x = t.x;
		int y = t.y;
		//cout << x << ' ' << y << endl;
		for (int i = 0; i < 4; i++) {
			int nx = x + dx[i];
			int ny = y + dy[i];
			if (nx >= 1 and ny >= 1 and nx <= n and ny <= n and vis[nx][ny] == 0 and a[x][y] != a[nx][ny]) {
				vis[nx][ny] = 1;
				q.push ({nx, ny});
				//cout << nx << ' ' << ny << endl;
				++ans;
			}
		}
	}
	return;
}

int main () {
	IOS;
	cin >> n >> m;
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= n; j++) {
			cin >> a[i][j];
		}
	}
	while (m--) {
		int i, j;
		cin >> i >> j;
		memset (vis, 0, sizeof (vis));
		bfs (i, j);
		cout << ans << endl;
		ans = 1;
	}
	return 0;
}