# include "bits/stdc++.h"
using namespace std;
using LL = long long;
using ULL = unsigned long long;
const double PI = acos(-1);
template<class T>constexpr T INF() { return ::std::numeric_limits<T>::max(); }
template<class T>constexpr T HINF() { return INF<T>() / 2; }
template <typename T_char>T_char TL(T_char cX) { return tolower(cX); };
template <typename T_char>T_char TU(T_char cX) { return toupper(cX); };
typedef pair<LL, LL> pii;
const int vy[] = { -1, -1, -1, 0, 1, 1, 1, 0 }, vx[] = { -1, 0, 1, 1, 1, 0, -1, -1 };
const int dx[4] = { 0,1,0,-1 }, dy[4] = { 1,0,-1,0 };
int popcnt(unsigned long long n) { int cnt = 0; for (int i = 0; i < 64; i++)if ((n >> i) & 1)cnt++; return cnt; }
int d_sum(LL n) { int ret = 0; while (n > 0) { ret += n % 10; n /= 10; }return ret; }
int d_cnt(LL n) { int ret = 0; while (n > 0) { ret++; n /= 10; }return ret; }
LL gcd(LL a, LL b) { if (b == 0)return a; return gcd(b, a%b); };
LL lcm(LL a, LL b) { LL g = gcd(a, b); return a / g*b; };
# define ALL(qpqpq)           (qpqpq).begin(),(qpqpq).end()
# define UNIQUE(wpwpw)        sort(ALL((wpwpw)));(wpwpw).erase(unique(ALL((wpwpw))),(wpwpw).end())
# define LOWER(epepe)         transform(ALL((epepe)),(epepe).begin(),TL<char>)
# define UPPER(rprpr)         transform(ALL((rprpr)),(rprpr).begin(),TU<char>)
# define FOR(i,tptpt,ypypy)   for(LL i=(tptpt);i<(ypypy);i++)
# define REP(i,upupu)         FOR(i,0,upupu)
# define INIT                 std::ios::sync_with_stdio(false);std::cin.tie(0)

LL calc1(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 + 1)*(by - ay + 1);
    bx -= ax;
    by -= ay;
    d -= ax + ay;
    LL ret = 0;
    if(d > by){
        ret = (by + 1)*(d - by);
        bx -= d - by;
        d -= d - by;
    }
    LL num = min(bx, d) + 1, s = d + 1, t = s - num + 1;
    ret += num*(d + 1 + t) / 2;
    return ret;
}

LL calc2(LL l, LL r, LL d){
    LL L = max(l, -d), R = min(r, d);
    if(L > R)return 0;
    return R - L + 1;
}


int main(){
    LL x1, x2, y1, y2, d;
    cin >> x1 >> y1 >> x2 >> y2 >> d;
    LL ans = 0;
    if(x2 > 0 && y2 > 0)ans += calc1(max(x1, 1LL), max(y1, 1LL), x2, y2, d);
    if(x1 < 0 && y2 > 0)ans += calc1(max(-x2, 1LL), max(y1, 1LL), -x1, y2, d);
    if(x1 < 0 && y1 < 0)ans += calc1(max(-x2, 1LL), max(-y2, 1LL), -x1, -y1, d);
    if(x2 > 0 && y1 < 0)ans += calc1(max(x1, 1LL), max(-y2, 1LL), x2, -y1, d);
    if(x1 <= 0 && 0 <= x2)ans += calc2(y1, y2, d);
    if(y1 <= 0 && 0 <= y2)ans += calc2(x1, x2, d);
    if(x1 <= 0 && y1 <= 0 && x2 >= 0 && y2 >= 0)ans--;
    cout << ans << endl;
}