n = int(input())
cheaters = set()
copied_from = []

for _ in range(n):
    a, b = input().split()
    cheaters.add(a)
    copied_from.append(b)

seen = set()
result = []

for b in copied_from:
    if b not in cheaters and b not in seen:
        result.append(b)
        seen.add(b)

print('\n'.join(result))