#include <iostream>
#include <set>
#include <queue>
#include <vector>
using namespace std;


int main() {

	int R,C;
	cin>>R>>C;
	
	int sx,sy,gx,gy;
	cin>>sx>>sy>>gx>>gy;;
	
	cout<<abs(sx-gx)+abs(sy-gy)<<endl;

    return 0;


}