N = int(input())
A = list(map(int, input().split()))
B = list(map(int, input().split()))
D = []
for a, b in zip(A, B):
    D.append((a, a + b))
    
D.sort()
M = 10 ** 6 + 5
dp = [0] * M
dp[1] = 1
for a, b in D:
    if not dp[a]:
        continue
    dp[b] = 1
    
for i in range(M - 1, 0, -1):
    if dp[i]:
        print(i)
        exit()