#include <bits/stdc++.h>

using std::cin;
using std::cout;

int main() {
	int a, b, c, d, m;
	cin >> a >> b >> c >> d >> m;

	if ((a + c) / m < (b + d) / m)
		cout << m - 1 << '\n';
	else
		cout << (b + d) % m << '\n';

	return 0;
}