#include <bits/stdc++.h>
using namespace std;
long long int INF = (long long int)1e16;
int n, m, r;
vector<int> s, b;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  s.clear();
  b.clear();
  cin >> n >> m >> r;
  int x, y;
  int bax = INT_MAX;
  int bay = INT_MIN;
  for (int i = 0; i < n; i++) {
    cin >> x;
    bax = min(bax, x);
  }
  for (int i = 0; i < m; i++) {
    cin >> y;
    bay = max(bay, y);
  }
  int bht = r / bax;
  int cost = bht * bay + r % bax;
  cout << max(cost, r) << endl;
  return 0;
}
