#include <bits/stdc++.h>

using namespace std;

using ll = long long;

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int r, c;
    cin >> r >> c;
    int sy, sx, gy, gx;
    cin >> sy >> sx >> gy >> gx;
    cout << abs(sy - gy) + abs(sx - gx) << endl;
    return 0;
}