#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b, c, d, e, f, r, ans = 0;
  scanf("%d%d%d%d%d%d", &a, &b, &c, &d, &e, &f);
  if (e > f) {
    r = min(d, a);
    ans += r * e;
    d -= r;
    ans += min(d, min(c, b)) * f;
  } else {
    r = min(d, min(c, b));
    ans += r * f;
    d -= r;
    ans += min(a, d) * e;
  }
  printf("%d\n", ans);
}
