ceil = lambda a, b: (a + b - 1) // b

def solve(D, X, Y):
    if X == Y == 0:
        return 0
    m = max(abs(X), abs(Y))
    res = ceil(m, max(D))
    if res == 1:
        res = 1 if m in D else 2
    return res

N = int(input())
D = set(map(int, input().split()))
X, Y = map(int, input().split())
print(solve(D, X, Y))