N = int(input())
A = input().split(' ')
B = input().split(' ')

acnt = {}

for a in A:
    acnt[a] = acnt.get(a, 0) + 1

bcnt = {}
for b in B:
    bcnt[b] = bcnt.get(b, 0) + 1

for k, v in acnt.items():
    if bcnt.get(k, 0) != v:
        print(k)
        break