#include <iostream>
#include <fstream>
#include <iomanip>
#include <string>
#include <vector>
#include <algorithm>
#include <cmath>
#include <math.h>
#include <set>
#include <map>
#include <queue>
#include <deque>
#include <stack>



using namespace std;



int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(0);

	unsigned long long a, k, b, kk, x;
	cin >> a >> k >> b >> kk >> x;

	unsigned long long d = 0, f = 0, ans = 0;
	unsigned long long l = 0;
	unsigned long long r = 2 * x / (a + b) + 1;

	while (r - l > 1)
	{
		ans = (r + l) / 2;
		d = (ans * a) - ((ans / k) * a);
		f = (ans * b) - ((ans / kk) * b);
		if (d + f >= x) r = ans;
	                	else l = ans;
	 }

	cout << ans;

}