from collections import defaultdict, deque

N = int(input())
A = list(map(int, input().split()))
B = list(map(int, input().split()))

adj = defaultdict(list)
for a, b in zip(A, B):
    adj[a].append(b)

ans = 1
used = set()
q = deque([1])
while q:
    x = q.popleft()
    if x in used: continue
    used.add(x)
    ans = max(ans, x)

    for v in adj[x]:
        if x+v in used: continue
        q.append(x+v)

print(ans)