#include<bits/stdc++.h>
using namespace std;
const int N=505;
int mp[N][N],t,ans=-0x7f,x,m,n,a,b,c,d;
int main(){
	ios::sync_with_stdio(false);
	cin>>m>>n;
	for(int i=0;i<m;i++)for(int j=0;j<n;j++)cin>>mp[i][j];
	for(int i=0;i<m;i++){
		for(int j=0;j<n;j++){
			cin>>x;
			if(x==1){
				if(i==0)a=0x7f;
				else a=abs(mp[i-1][j]-mp[i][j]);
				
				if(j==0)b=0x7f;
				else b=abs(mp[i][j-1]-mp[i][j]);
				
				if(i==m-1)c=0x7f;
				else c=abs(mp[i+1][j]-mp[i][j]);
				
				if(j==n-1)d=0x7f;
				else d=abs(mp[i][j+1]-mp[i][j]);
			}
			ans=max(ans,min(min(a,b),min(c,d)));
		}
		
	}
	cout<<ans;
	return 0;
}

rt

求调