from operator import itemgetter

N = int(input())
A = []
B = {}
for i in range(N):
    a, b = input().split()
    A.append(a)
    if b not in B:
        B[b] = i

for a in A:
    if a in B:
        del B[a]

C = sorted(B.items(), key=itemgetter(1))

for k, _ in C:
    print(k)