#include <bits/stdc++.h>
#define GET_MACRO(a, b, c, NAME, ...) NAME
#define rep(...) GET_MACRO(__VA_ARGS__, rep3, rep2)(__VA_ARGS__)
#define rep2(i, a) rep3 (i, 0, a)
#define rep3(i, a, b) for (int i = (a); i < (b); i++)
#define repr(...) GET_MACRO(__VA_ARGS__, repr3, repr2)(__VA_ARGS__)
#define repr2(i, a) repr3 (i, 0, a)
#define repr3(i, a, b) for (int i = (b) - 1; i >= (a); i--)
template<class T1, class T2> inline bool chmin(T1 &a, T2 b) { return b < a && (a = b, true); }
template<class T1, class T2> inline bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); }
using namespace std;
typedef long long ll;

typedef ll D;
typedef complex<D> P;
const D eps = 0;

D dot(P a, P b) {
	return real(conj(a) * b);
}

D cross(P a, P b) {
	return imag(conj(a) * b);
}

bool comp(P a, P b) {
	if (a.real() != b.real()) return a.real() < b.real();
	return a.imag() < b.imag();
}

vector<P> convexfull(vector<P> &ps) {
	int n = ps.size();
	sort(ps.begin(), ps.end(), comp);
	int k = 0;
	vector<P> qs(n * 2);
	for (int i = 0; i < n; i++) {
		while (k > 1 && cross(qs[k - 1] - qs[k - 2], ps[i] - qs[k - 1]) <= 0) k--;
		qs[k++] = ps[i];
	}
	for (int i = n - 2, t = k; i >= 0; i--) {
		while (k > t && cross(qs[k - 1] - qs[k - 2], ps[i] - qs[k - 1]) <= 0) k--;
		qs[k++] = ps[i];
	}
	qs.resize(k - 1);
	return qs;
}

int ccw(P a, P b, P c) {
	b -= a; c -= a;
	if (cross(b, c) > eps) return 1;
	if (cross(b, c) < -eps) return -1;
	if (dot(b, c) < -eps) return 2;
	if (norm(b) < norm(c)) return -2;
	return 0;
}

bool intersectSS(P p1, P p2, P p3, P p4) {
	return ccw(p1, p2, p3) * ccw(p1, p2, p4) <= 0 &&
		ccw(p3, p4, p1) * ccw(p3, p4, p2) <= 0;
}

P intersection(P p1, P p2, P q1, P q2) {
	P base = q2 - q1;
	D d1 = abs(cross(base, p1 - q1));
	D d2 = abs(cross(base, p2 - q1));
	D g = __gcd(d1, d2);
	d1 /= g; d2 /= g;
	return (p1 * d2 + p2 * d1) / (d1 + d2);
}

bool contains(P r, vector<P> poly) {
	int n = poly.size();
	int count = 0;
	rep (i, n) {
		P p = poly[(i + 1) % n] - poly[i], q = r - poly[i];
		if (cross(p, q) >= -eps) count++;
	}
	return count == n;
}

vector<P> convex_intersection(vector<P> ps, vector<P> qs) {
	vector<P> rs;
	int a = ps.size(), b = qs.size();
	rep (i, a) if (contains(ps[i], qs)) rs.push_back(ps[i]);
	rep (i, b) if (contains(qs[i], ps)) rs.push_back(qs[i]);
	rep (i, a) rep (j, b) {
		P p1 = ps[i], p2 = ps[(i + 1) % a];
		P q1 = qs[j], q2 = qs[(j + 1) % b];
		if (intersectSS(p1, p2, q1, q2)) {
			rs.push_back(intersection(p1, p2, q1, q2));
		}
	}
	sort(rs.begin(), rs.end(), comp);
	rs.erase(unique(rs.begin(), rs.end()), rs.end());
	if (rs.size() <= 1) return rs;
	return convexfull(rs);
}

D count_lattice(P p, P q) {
	D dx = abs(real(p) - real(q));
	D dy = abs(imag(p) - imag(q));
	return __gcd(dx, dy);
}

D count_lattice(vector<P> ps) {
	int n = ps.size();
	if (n == 0) return 0;
	D b = 0, S = 0;
	rep (i, n) {
		P p = ps[i], q = ps[(i + 1) % n];
		b += count_lattice(p, q);
		S += cross(p, q);
	}
	return b + (S - b + 2) / 2;
}

int main() {
	D x1, y1, x2, y2, d;
	cin >> x1 >> y1 >> x2 >> y2 >> d;

	if (d == 0) {
		if (x1 <= 0 && 0 <= x2 && y1 <= 0 && 0 <= y2) {
			cout << 1 << endl;
		} else {
			cout << 0 << endl;
		}
		return 0;
	}

	vector<P> R1 = {{x1, y1}, {x2, y1}, {x2, y2}, {x1, y2}};
	vector<P> R2 = {{d, 0}, {0, d}, {-d, 0}, {0, -d}};
	cout << (ll)count_lattice(convex_intersection(R1, R2)) << endl;
	return 0;
}