#include "bits/stdc++.h"
using namespace std;
#define int long long
#define FOR(i, a, b) for(int i=(a);i<(b);i++)
#define RFOR(i, a, b) for(int i=(b-1);i>=(a);i--)
#define REP(i, n) for(int i=0; i<(n); i++)
#define RREP(i, n) for(int i=(n-1); i>=0; i--)
#define ALL(a) (a).begin(),(a).end()
#define UNIQUE_SORT(l) sort(ALL(l)); l.erase(unique(ALL(l)), l.end());
#define CONTAIN(a, b) find(ALL(a), (b)) != (a).end()
#define array2(type, x, y) array<array<type, y>, x>
#define vector2(type) vector<vector<type> >
#define out(...) printf(__VA_ARGS__)

int dxy[] = {0, 1, 0, -1, 0};

void solve();
signed main()
{
#if DEBUG
    std::ifstream in("input.txt");
    std::cin.rdbuf(in.rdbuf());
#endif
    cin.tie(0);
    ios::sync_with_stdio(false);
    solve();
    return 0;
}

/*================================*/


struct Pos {
    int x, y;
    Pos(){};
    Pos(int _x, int _y): x(_x), y(_y){};
    
    Pos operator * (int t) {
        return Pos(t * x, t * y);
    }
    Pos operator + (Pos q) {
        return Pos(x + q.x, y + q.y);
    }
    Pos operator - (Pos q) {
        return Pos(x - q.x, y - q.y);
    }
    int dot(Pos q) {
        return x * q.x + y * q.y;
    }
    int det(Pos q) {
        return x * q.y - y * q.x;
    }
    bool operator == (Pos q) {
        return (x == q.x) && (y == q.y);
    }
};

void rotate(Pos *r) {
    int tmp = r->x;
    r->x = r->y;
    r->y = -tmp;
}

int D;
Pos p,q;

int count(int i) {
    int minx = max((int)1, min(p.x, q.x));
    int maxx = max(p.x, q.x);
    int miny = max((int)0, min(p.y, q.y));
    int maxy = max(p.y, q.y);
    if (maxx < minx || maxy < miny) return 0;
    if (D < minx || D < miny) return 0;
    int base = min(maxx, D) - minx - miny + 1;
    int height = min(maxy, D) - miny + 1;
    int top = base - height + 1;
    return max((int)0, height * (base + top) / 2);
}

void solve() {
    cin>>p.x>>p.y>>q.x>>q.y>>D;
    
    int ans = 0;
    REP(i,4) {
        ans += count(i);
        rotate(&p);
        rotate(&q);
    }
    // 原点を含む場合
    if (p.x<=0&&0<=q.x&&p.y<=0&&0<=q.y) ans++;
    
    cout << ans << endl;
}