#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 1010;
int n,m,ans,sum[1010100];
char mp[N][N];
bool vis[N][N];
int dx[] = {0,0,1,-1},dy[] = {1,-1,0,0};
int f[1010100];
int find(int p)
{
	if(p!=f[p]) f[p] = find(f[p]);
	return f[p];
}
void dfs(int x,int y)
{	
	if(ans == n*n) return;
	for(int i=0;i<4;i++)
	{
		int tx = x+dx[i],ty = y+dy[i];
		if(tx<=0||tx>n||ty<=0||ty>n) continue;
		if(vis[tx][ty]) continue;
		if(mp[tx][ty] == mp[x][y]) continue;
		vis[tx][ty] = 1;
		f[(tx-1)*n+ty] = find((x-1)*n+y);
		ans ++;
		dfs(tx,ty);
	}
	return;
}
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0),cout.tie(0);
	
	cin>>n>>m;
	for(int i = 1;i<=n;i++)
	{
		string s;
		cin>>s;
		for(int j = 0;j<n;j++)
		{
			mp[i][j+1] = s[j];
		}
	}	
	for(int i = 1;i<=n;i++)
	{
		for(int j = 1;j<=n;j++)
		{
			int idx = (i-1)*n+j;
			f[idx] = idx;
		}
	}
	for(int i = 1;i<=m;i++)
	{
		int x,y;
		ans = 1;
		cin>>x>>y;
		if(sum[find((x-1)*n+y)]) cout<<sum[find((x-1)*n+y)]<<endl;
		else
		{
			vis[x][y] = 1;
			ans = 1;
			dfs(x,y);
			sum[(x-1)*n+y] = ans;
			cout<<ans<<endl;
		}
		
	}
	return 0;
}

dfs+并查集优化（（（））））