#include <fstream>
#include <queue>
using namespace std;
ifstream fin("minim2.in");
ofstream fout("minim2.out");
int n, i, j, k, x[100001];
double a, b, goal, s;

int main()
{
    fin >> n;
    for (i = 1; i <= n; i++)
    {
        fin >> x[i];
        s += x[i];
    }
    fin >> a >> b >> goal;
    priority_queue <pair<double, int>> q;
    for (i = 1; i <= n; i++)
        q.push({x[i]-x[i]*a, i});
    while (s > goal)
    {
        s -= q.top().first;
        i = q.top().second;
        x[i] -= q.top().first;
        q.pop();
        q.push({x[i]-x[i]*b, i});
        k++;
    }
    fout << k;
    return 0;
}