#include<bits/stdc++.h>
using namespace std;
const int N = 1e5 + 6;
int n,m;
string a[N];
int ans = 0;
bool aa[N][N];
int dis(int q){
	return q == 0;
}
void dfs(int x,int y,int z,int q){
	if (x < 1 || y < 1 || x > n || y > n || aa[x][y] == true || a[x][y] != q){
		if (z > ans)ans = z;
		return;
	}
	aa[x][y] = true;
	z++;
	dfs(x - 1,y,z,dis(q));
	dfs(x + 1,y,z,dis(q));
	dfs(x,y - 1,z,dis(q));
	dfs(x,y + 1,z,dis(q));
}
int main(){
	scanf("%d%d",&n,&m);
    for (int i = 1;i <= n;++i)cin>>a[i];
    for (int i = 1;i <= m;++i){
		int x,y,q;
		scanf("%d%d",&x,&y);
        ans = 0;
		if (a[x][y] == '0')q = 0;
		else q = 1;
		dfs(x,y,0,q);
		printf("%d\n",ans);
	}
	return 0;
}