#include<iostream>
#include<string>
#include<iomanip>
#include<cmath>
#include<vector>
#include<algorithm>
#include<utility>
#include<queue>

using namespace std;

#define int long long
#define endl "\n"

constexpr long long INF = (long long)1e18;
constexpr long long MOD = 1'000'000'007; 

struct fast_io {
	fast_io(){
		std::cin.tie(nullptr);
		std::ios::sync_with_stdio(false);
	};
} fio;



signed main(){
	cout<<fixed<<setprecision(10);
	
	int R, C;
	int sy, sx;
	int gy, gx;
	vector<string> c;
	
	cin>>R>>C;
	
	cin>>sy>>sx;
	
	cin>>gy>>gx;
	
	cout<<abs(sy-gy)+abs(gx-sx)<<endl;
	c.resize(R);
	

	
	return 0;
}