#include <bits/stdc++.h> 

using namespace std;
using ll=long long;
using ull=unsigned long long;
using pii=pair<int,int>;

#define INF LONG_MAX
#define MOD 1000000007
#define rng(a) a.begin(),a.end()
#define rrng(a) a.end(),a.begin()
#define endl "\n"

int main(){
  ios::sync_with_stdio(false);
  cin.tie(0);

  int R,C,sy,sx,gy,gx;
  cin>>R>>C>>sy>>sx>>gy>>gx;
  vector<string>c(R);
  for(int i=0;i<R;i++)cin>>c[i];
  cout<<abs(sx-gx)+abs(sy-gy)<<endl;
  return 0;
}