#include <bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define ld long double
#define len(v) (int)v.size()
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define pii pair<int, int>
#define vi vector<int>
#define vii vector<vector<int>>
#define vpii vector<pair<int, int>>
#define ull unsigned long long
#define dcout cout << setprecision(7)
//#define int long long
//#define ll ull
const int maxn = 110;
const int C = 20;
const int logn = 20;
const int inf = 1e9;
const ll mod = 1e9 + 7;
const int M = 1e9;
const ull M2 = 998244353;
const ld eps = 1e-9;
using namespace std;

// random
//std::mt19937_64 gen(std::chrono::steady_clock::now().time_since_epoch().count());

template<class T>
istream &operator>>(istream &in, vector<T> &a) {
    for (auto &i : a)
        in >> i;
    return in;
}

template<class T>
ostream &operator<<(ostream &out, vector<T> &a) {
    for (auto &i : a)
        out << i;
    return out;
}

int binpow (int a, int n) {
    if (n == 0)
        return 1;
    if (n % 2 == 1)
        return binpow (a, n-1) * a;
    else {
        int b = binpow (a, n/2);
        return b * b;
    }
}

__int128 a, b, k, m, x;

bool ok (__int128 d) {
    __int128 s = (d-(d/k))*a;
    s += (d-(d/m))*b;

    if (s>=x)
        return true;
    return false;
}

void print(__int128 x) {
    if (x < 0) {
        putchar('-');
        x = -x;
    }
    if (x > 9) print(x / 10);
    putchar(x % 10 + '0');
}

__int128 read() {
    __int128 x = 0, f = 1;
    char ch = getchar();
    while (ch < '0' || ch > '9') {
        if (ch == '-') f = -1;
        ch = getchar();
    }
    while (ch >= '0' && ch <= '9') {
        x = x * 10 + ch - '0';
        ch = getchar();
    }
    return x * f;
}

void solve() {
    a = read();
    k = read();
    b = read();
    m = read();
    x = read();
    __int128 l = 0ull, r = x;
    while (l + 1 < r) {
        __int128 mid = (l + r) / 2ull;
        if (ok(mid))
            r = mid;
        else
            l = mid;
    }
    print(r);
}

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);

    int T = 1;
    //cin >> T;
    while (T--) {
        solve();
    }
}