#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <iomanip>
#include <cmath>
#include <stdio.h>
#include <queue>
#include <deque>
#include <cstdio>
#include <set>
#include <map>
#include <bitset>
#include <stack>
#include <cctype>
using namespace std;
int main(){
	int r, c, s1, s2, g1, g2;
	cin >> r >> c >> s1 >> s2 >> g1 >> g2;
	string s[1000];
	for (int i = 0; i < r; i++) {
		cin >> s[i];
	}
	cout << abs(g1 + g2 - s1 - s2) << endl;
	return 0;
}