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

C = [(A[i],B[i]) for i in range(N)]
C.sort()
s = set()
s.add(1)
for a,b in C:
	if a in s:
		s.add(a + b)
print(max(s))