#include <iostream>
#include <cmath>

void solve() {
    int r, c, x1, y1, x2, y2;
    std::cin >> r >> c >> x1 >> y1 >> x2 >> y2;
    std::cout << std::abs(x1 - x2) + std::abs(y1 - y2) << std::endl;
}

int main() {
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    solve();

    return 0;
}