#include<iostream>
#include<vector>
#include<string>
#include<array>
#include<algorithm>
#include<list>
#include<cmath>
#include<iomanip>
#include<queue>
#include<functional>
#include<climits>
#include<iterator>
#include<unordered_set>
#include<unordered_map>
#include<map>
#include<set>
#include<typeinfo>
using namespace std;

const double pi=4*atan(1.0);

constexpr long long mod=static_cast<long long>(1e9+7);

using cWeightEdges=vector<vector<pair<int,int>>>;
using cEdges=vector<vector<int>>;

int main() {
	int h,w;
	cin>>h>>w;
	int Sx,Sy,Gx,Gy;
	cin>>Sx>>Sy>>Gx>>Gy;
	--Sx,--Sy,--Gx,--Gy;
	vector<vector<int>> Height(h,vector<int>(w,0));
	for(auto& val:Height){
		string str;
		cin>>str;
		for(int i=0;i<w;++i){
			val[i]=str[i]-'0';
		}
	}
	
	vector<vector<bool>> memo(h,vector<bool>(w,0));
	queue<pair<int,int>> Q;
	Q.push(make_pair(Sx,Sy));
	memo[Sx][Sy]=true;
	bool IsFind=false;
	while(!Q.empty()){
		auto now=Q.front();
		Q.pop();
		if(now.first==Gx && now.second==Gy){
			IsFind=true;
			break;
		}

		if(now.first+1<h && Height[now.first][now.second]-1<=Height[now.first+1][now.second] && Height[now.first+1][now.second]<=Height[now.first][now.second]+1 && !memo[now.first+1][now.second]){
			memo[now.first+1][now.second]=true;
			Q.push(make_pair(now.first+1,now.second));
		}

		if(0<=now.first-1 && Height[now.first][now.second]-1<=Height[now.first-1][now.second] && Height[now.first-1][now.second]<=Height[now.first][now.second]+1 && !memo[now.first-1][now.second]){
			memo[now.first-1][now.second]=true;
			Q.push(make_pair(now.first-1,now.second));
		}

		if(now.second+1<w && Height[now.first][now.second]-1<=Height[now.first][now.second+1] && Height[now.first][now.second+1]<=Height[now.first][now.second]+1 && !memo[now.first][now.second+1]){
			memo[now.first][now.second+1]=true;
			Q.push(make_pair(now.first,now.second+1));
		}

		if(0<=now.second-1 && Height[now.first][now.second]-1<=Height[now.first][now.second-1] && Height[now.first][now.second-1]<=Height[now.first][now.second]+1 && !memo[now.first][now.second-1]){
			memo[now.first][now.second-1]=true;
			Q.push(make_pair(now.first,now.second-1));
		}

		if(now.first+2<h && Height[now.first][now.second]==Height[now.first+2][now.second] && Height[now.first+1][now.second]<Height[now.first][now.second] && !memo[now.first+2][now.second]){
			memo[now.first+2][now.second]=true;
			Q.push(make_pair(now.first+2,now.second));
		}

		if(0<=now.first-2 && Height[now.first][now.second]==Height[now.first-2][now.second] && Height[now.first-1][now.second]<Height[now.first][now.second] && !memo[now.first-2][now.second]){
			memo[now.first-2][now.second]=true;
			Q.push(make_pair(now.first-2,now.second));
		}

		if(now.second+2<w && Height[now.first][now.second]==Height[now.first][now.second+2] && Height[now.first][now.second+1]<Height[now.first][now.second] && !memo[now.first][now.second+2]){
			memo[now.first][now.second+2]=true;
			Q.push(make_pair(now.first,now.second+2));
		}

		if(0<=now.second-2 && Height[now.first][now.second]==Height[now.first][now.second-2] && Height[now.first][now.second-1]<Height[now.first][now.second] && !memo[now.first][now.second-2]){
			memo[now.first][now.second-2]=true;
			Q.push(make_pair(now.first,now.second-2));
		}
	}

	if(IsFind)cout<<"YES"<<endl;
	else cout<<"NO"<<endl;

	//system("pause");
	return 0;
}