#include"bits/stdc++.h"
using namespace std;
#define REP(k,m,n) for(int (k)=(m);(k)<(n);(k)++)
#define rep(i,n) REP((i),0,(n))
using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using tp3 = tuple<int, int, int>;
using Mat = vector<vector<ll>>;
constexpr int INF = 1 << 28;
constexpr ll INFL = 1ll << 60;
constexpr int dh[4] = { 0,1,0,-1 };
constexpr int dw[4] = { -1,0,1,0 };
bool isin(const int H, const int W, const int h, const int w) {
    return 0 <= h && h < H && 0 <= w && w < W;
}
template<typename T>
T minch(T& l, T r) {
    return l = min(l, r);
}
template<typename T>
T maxch(T& l, T r) {
    return l = max(l, r);
}
template<typename T>
void output(const T& val) {
    cout << val << endl;
}
template<typename T>
void output(const vector<T>& vec, const bool newline = false) {
    for (const T& val : vec)cout << val << (newline ? '\n' : ' '); cout << endl;
}
template<typename T>
void output(const vector<vector<T>>& mat) {
    for (const auto& row : mat)output(row);
}
// ============ template finished ============

int main()
{
    int R, C;
    pii s, g;
    cin >> R >> C >> s.first >> s.second >> g.first >> g.second;
    s.first--, s.second--, g.first--, g.second--;
    cout << abs(s.first - g.first) + abs(s.second - g.second) << endl;
    return 0;
    vector<string> c(R);
    rep(i, R)cin >> c[i];

    Mat d(R, vector<ll>(C, INFL));
    priority_queue<tp3, vector<tp3>, greater<tp3>> pq;
    d[s.first][s.second] = 0;
    pq.push(make_tuple(0, s.first, s.second));
    while (!pq.empty()) {
        int p, h, w;
        tie(p, h, w) = pq.top(); pq.pop();
        rep(dir, 4) {
            int nr = h + dh[dir], nc = w + dw[dir];
            if (nr < 0)nr = R - 1;
            if (R <= nr)nr = 0;
            if (nc < 0)nc = C - 1;
            if (C <= nc)nc = 0;
            if (c[nr][nc] == '#' || d[nr][nc] <= p + 1)continue;
            d[nr][nc] = p + 1;
            pq.push(make_tuple(p + 1, nr, nc));
        }
    }
    output(d[g.first][g.second]);
    return 0;
}