import sys
input=lambda: sys.stdin.readline().rstrip()
n=int(input())
A,B=set(),[]
for _ in range(n):
  a,b=map(str,input().split())
  A.add(a)
  B.append(b)
C=set()
for b in B:
  if b not in A and b not in C:
    print(b)
    C.add(b)