// I SELL YOU...! 
#include<iostream>
#include<vector>
#include<algorithm>
#include<functional>
#include<queue>
#include<chrono>
#include<iomanip>
#include<map>
#include<set>
using namespace std;
using ll = long long;
using P = pair<ll,ll>;
using TP = tuple<ll,ll,ll>;
void init_io(){
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << setprecision(10);
}
signed main(){
  init_io();
  ll r,c,sy,sx,gy,gx;
  cin >> r >> c >> sy >> sx >> gy >> gx;
  cout << abs(sx-gx) + abs(gy-sy)<<endl;
}