#要はxとyの値の大きい方に引っ張られる距離だな
n = int(input())
d = sorted([int(i) for i in input().split()])
x, y = [abs(int(i)) for i in input().split()]
def func(n, d, x, y):
    d_max = d[-1]
    ans = -1
    if max(x, y)==0:
        ans=0
    else:
        for m in d:
            if m==max(x, y):
                ans = 1
    if ans==-1:
        if max(x, y)>2*d_max:
            c = max(x, y)//d_max
            if max(x,y)%d_max==0:
                ans+=c+1
            else:
                ans+=c+2
        else:
            ans=2
    return ans

print(func(n, d, x, y))