#include <bits/stdc++.h>
const int INF = 0x3f3f3f3f;
const int MAXNN = 1000050;
const int MAXN = 300050;
const double eps = 1e-8;
using namespace std;
int main() {
  int a, b, c, d, e, f;
  cin >> a >> b >> c >> d >> e >> f;
  int ans = 0;
  if (e > f) {
    ans += min(a, d) * e;
    d -= min(a, d);
    ans += min(min(b, c), d) * f;
  } else {
    ans += min(min(b, c), d) * f;
    d -= min(min(b, c), d);
    ans += min(a, d) * e;
  }
  cout << ans << endl;
  return 0;
}
