#include <bits/stdc++.h>
long long int MMM = 1000000007;
int pw(long long int a, long long int b) {
  if (b == 0) return 1;
  long long int t = pw(a, b / 2);
  if (b % 2 == 0)
    return (t * t) % 1000000007;
  else
    return ((t * t) % 1000000007 * a) % 1000000007;
}
using namespace std;
vector<int> pm;
void prm(int n) {
  bool prime[n + 1];
  memset(prime, true, sizeof(prime));
  for (int p = 2; p * p <= n; p++) {
    if (prime[p] == true) {
      for (int i = p * p; i <= n; i += p) prime[i] = false;
    }
  }
  for (int p = 2; p <= n; p++)
    if (prime[p]) pm.push_back(p);
}
bool sortbysecdesc(const pair<long long int, long long int> &a,
                   const pair<long long int, long long int> &b) {
  return a.first > b.first;
}
bool cmp(int x, int y) { return x > y; }
long long int gcd(long long int a, long long int b) {
  if (!a) return b;
  return gcd(b % a, a);
}
int pa[26];
int find(int i) {
  if (i == pa[i]) return i;
  return pa[i] = find(pa[i]);
}
void join(int i, int j) {
  int a = find(i);
  int b = find(j);
  if (b >= a)
    pa[b] = a;
  else
    pa[a] = b;
}
int dx[] = {-1, -1, -1, 0, 1, 1, 1, 0};
int dy[] = {-1, 0, 1, 1, 1, 0, -1, -1};
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long int a, b, c, d, e, f;
  cin >> a >> b >> c >> d >> e >> f;
  if (e >= f) {
    long long min1 = min(a, d) * e;
    d -= min(a, d);
    long long min2 = min(b, min(c, d)) * f;
    cout << min1 + min2;
  } else {
    long long min2 = min(b, min(c, d)) * f;
    d -= min(b, min(c, d));
    long long min1 = min(a, d) * e;
    cout << min1 + min2;
  }
}
