#include <iostream>
#include <algorithm>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll = long long;
//#define endl "\n";
const vector<int> dx = {1, 0, -1, 0};
const vector<int> dy = {0, 1, 0, -1};
queue<pair<int, int>> que;
ll visitedAB[209][209];
ll visitedPQ[209][209];
ll H, W;
ll A, B;
ll r1,r2,c1,c2;
ll P, Q;

int main(){
    cin >> H >> W;
    cin >> A >> B;
    A--, B--;
    cin >> r1 >> c1 >> r2 >> c2;
    r1--, r2--, c1--, c2--;
    cin >> P >> Q;
    P--, Q--;
    for(int i = 0; i < H; i++){
        for(int j = 0; j < W; j++){
            visitedAB[i][j] = -1;
        }
    }
    visitedAB[A][B] = 0;
    que.push({A, B});
    while(que.size() > 0){
        auto [h, w] = que.front(); que.pop();
        for(int k = 0; k < 4; k++){
            if(h + dy[k] < 0 || H <= h + dy[k]) continue;
            if(w + dx[k] < 0 || W <= w + dx[k]) continue;
            if(visitedAB[h + dy[k]][w + dx[k]] == -1){
                visitedAB[h + dy[k]][w + dx[k]] = visitedAB[h][w] + 1;
                que.push({h + dy[k], w + dx[k]});
            }
        }
    }
    for(int i = 0; i < H; i++){
        for(int j = 0; j < W; j++){
            visitedPQ[i][j] = -1;
        }
    }
    visitedPQ[P][Q] = 0;
    que.push({P, Q});
    while(que.size() > 0){
        auto [h, w] = que.front(); que.pop();
        for(int k = 0; k < 4; k++){
            if(h + dy[k] < 0 || H <= h + dy[k]) continue;
            if(w + dx[k] < 0 || W <= w + dx[k]) continue;
            if(visitedPQ[h + dy[k]][w + dx[k]] == -1){
                visitedPQ[h + dy[k]][w + dx[k]] = visitedPQ[h][w] + 1;
                que.push({h + dy[k], w + dx[k]});
            }
        }
    }
    ll ans = 1e9;
    ll ABPQ = abs(A - P) + abs(B - Q);
    for(int i = r1; i <= r2; i++){
        for(int j = c1; j <= c2; j++){
            ans = min(ans, visitedAB[i][j] + visitedPQ[i][j] + ABPQ);
        }
    }
    cout << ans << endl;
    return 0;
}