#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, m, r, i, an = 1100, bn = 0;
  cin >> n >> m >> r;
  int a, b;
  for (i = 0; i < n; i++) {
    cin >> a;
    if (an > a) an = a;
  }
  for (i = 0; i < m; i++) {
    cin >> b;
    if (bn < b) bn = b;
  }
  if (bn > an) {
    r = (bn) * (r / an) + (r - (r / an) * an);
  }
  cout << r;
  return 0;
}
