#include "bits/stdc++.h"
using namespace std;
#define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i))
#define rep(i,j) FOR(i,0,j)
#define each(x,y) for(auto &(x):(y))
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define debug(x) cout<<#x<<": "<<(x)<<endl
#define smax(x,y) (x)=max((x),(y))
#define smin(x,y) (x)=min((x),(y))
#define MEM(x,y) memset((x),(y),sizeof (x))
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<ll> vll;

ll f(ll ax, ll ay, ll bx, ll by, ll d){
    if(ax > bx || ay > by || ax + ay > d)return 0;
    if(bx + by <= d)return (bx - ax)*(by - ay);
    bx -= ax;
    by -= ay;
    d -= ax + ay;
    ll res = 0;
    if(d > by){
        res = (by + 1)*(d - by);
        bx -= d - by;
        d -= d - by;
    }
    ll len = min(bx, d) + 1, s = d + 1, t = s - len + 1;
    res += len*(d + 1 + t) / 2;
    return res;
}

ll g(ll l, ll r, ll d){
    ll L = max(l, -d), R = min(r, d);
    if(L > R)return 0;
    return R - L + 1;
}

ll ax, ay, bx, by, d;

int main(){
    ios::sync_with_stdio(0);
    cin.tie(0);
    cin >> ax >> ay >> bx >> by >> d;
    ll ans = 0;
    if(bx > 0 && by > 0)ans += f(max(ax, 1ll), max(ay, 1ll), bx, by, d);
    if(ax < 0 && by > 0)ans += f(max(-bx, 1ll), max(ay, 1ll), -ax, by, d);
    if(ax < 0 && ay < 0)ans += f(max(-bx, 1ll), max(-by, 1ll), -ax, -ay, d);
    if(bx > 0 && ay < 0)ans += f(max(ax, 1ll), -max(-by, 1ll), bx, -ay, d);
    if(ax <= 0)ans += g(ay, by, d);
    if(ay <= 0)ans += g(ax, bx, d);
    if(ax <= 0 && ay <= 0)ans--;
    cout << ans << endl;
}