#include <bits/stdc++.h>

using namespace std;

#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()

template<typename A, typename B> inline bool chmax(A &a, B b) { if (a<b) { a=b; return 1; } return 0; }
template<typename A, typename B> inline bool chmin(A &a, B b) { if (a>b) { a=b; return 1; } return 0; }

typedef unsigned long long ull;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<int, pii> P;

const ll INF = 1ll<<60;
const ll MOD = 1000000007;
const double EPS  = 1e-10;

int n;
ll d[15];
ll x, y;

int main() {
	cin >> n;
	REP(i, n) scanf("%lld", d + i);
	cin >> x >> y;
	
	sort(d, d + n);
	
	ll nec = max(abs(x), abs(y));
	
	ll ans = INF;
	FOR(i, 1, 1 << n) {
		ll now = 0, cnt = 0;
		REP(j, n) if (i >> j & 1) {
			now += d[j];
			cnt++;
		}
		
		if (nec % now == 0) chmin(ans, nec / now * cnt);
		
		if (now > nec) {
			for (int j = n - 1; j >= 0; j--) if (!(i >> j & 1)) {
				if (now > nec) now -= d[j], cnt++;
			}
			chmin(ans, cnt);
		}
	}
	
	if (ans == INF) puts("-1");
	else cout << ans << endl;
	
	return 0;
}