/*
         --┬--  |     |  --┬--                |       |
           |    |\    |    |                  |       |
           |    | \   |    |     ----->       |       |
           |    |  \  |    |                  |       |
           |    |   \ |    |                  |       |
         --┴--  |    \|    |                  └----   └----

*/

// #define pragma

#ifdef pragma
#pragma GCC optimize("Ofast")
#pragma GCC optimize("no-stack-protector")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#pragma GCC optimize("unroll-loops")
#pragma GCC diagnostic ignored "-Wunused-result"
#endif // pragma

#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

#define ll long long
#define all(x) begin(x), end(x)
#define pb push_back
// #define x first
// #define y second
#define int long long
#define zero(x) memset(x, 0, sizeof(x))

using namespace std;
using namespace __gnu_pbds;


typedef vector<int> vi;
typedef vector<bool> vb;
typedef pair<int, int> pii;
typedef long double ld;
typedef vector<vi> matrix;
typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;

const int INF = 1e9 + 7;
const ld EPS = 1e-9;
const ld PI = atan2(0, -1);

void seriy() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    cout << fixed << setprecision(7);
    cerr << fixed << setprecision(7);
    #if 1
        freopen("input", "r", stdin);
        freopen("output", "w", stdout);
    #endif
}

int x, y, x2, y2, x3, y3, x4, y4;

bool incb(int l, int r, int d, int u) {
    if(l >= x3 && l <= x4 && r >= x3 && r <= x4 && d >= y3 && d <= y4 && u >= y3 && u <= y4) {
       return 1;
    }
    return 0;
}

bool incw(int l, int r, int d, int u) {
    if(l >= x && l <= x2 && r >= x && r <= x2 && d >= y && d <= y2 && u >= y && u <= y2) {
       return 1;
    }
    return 0;
}

int p(int l, int r, int d, int u) {
    int cnt1, cnt2, ans;
    if(d % 2) {
        if(l % 2) {
            cnt1 = (r - l + 1) / 2 + (r - l + 1) % 2;
            cnt2 = (r - l + 1) / 2;
        }
        else {
            cnt1 = (r - l + 1) / 2;
            cnt2 = (r - l + 1) / 2 + (r - l + 1) % 2;
        }
        ans = ((u - d + 1) / 2) * cnt1 + ((u - d + 1) / 2) * cnt2 + ((u - d + 1) % 2) * cnt1;
    }
    else {
        if(l % 2) {
            cnt1 = (r - l + 1) / 2;
            cnt2 = (r - l + 1) / 2 + (r - l + 1) % 2;
        }
        else {
            cnt1 = (r - l + 1) / 2 + (r - l + 1) % 2;
            cnt2 = (r - l + 1) / 2;
        }
        ans = ((u - d + 1) / 2) * cnt1 + ((u - d + 1) / 2) * cnt2 + ((u - d + 1) % 2) * cnt1;
    }
    return ans;
}

signed main() {
    seriy();
    int n, m;
    cin >> n >> m;
    cin >> x >> y >> x2 >> y2 >> x3 >> y3 >> x4 >> y4;
    vi xs = {x, x2, x3, x4};
    vi ys = {y, y2, y3, y4};
    sort(all(xs));
    sort(all(ys));
    int ans = 0;
    for(int i = 0; i < 3; i++) {
        for(int j = 0; j < 3; j++) {
            int l = xs[i], r = xs[i + 1];
            int d = ys[j], u = ys[j + 1];
            if(incb(l, r, d, u)) {
                ans += (r - l + 1) * (u - d + 1);
            }
            else if(incw(l, r, d, u)) {
                continue;
            }
            else {
                ans += p(l, r, d, u);
            }
        }
    }
    cerr << ans;
    ans += p(1, xs[0], 1, n);
    ans += p(xs[3], m, 1, n);
    ans += p(xs[0], xs[3], 1, ys[0]);
    ans += p(xs[0], xs[3], ys[3], n);
    cout << ans;
    return 0;
}