#import pysnooper
#import numpy
#import os,re,sys,operator
#from collections import Counter,deque
#from operator import itemgetter,mul
#from itertools import accumulate#,combinations,groupby,combinations_with_replacement,permutations
from sys import stdin,setrecursionlimit
#from bisect import bisect_left,bisect_right
#from copy import deepcopy
#import heapq
#import math
#import string
#from time import time
#from functools import lru_cache,reduce
#from math import factorial
#import sys

setrecursionlimit(10**6)
input=stdin.readline

n=int(input().rstrip())
ans=set()
d=set()
r=[]
info=[]
for i in range(n):
    a,b=input().split()
    info.append(b)
    d.add(a)
    ans.add(b)
for i in ans:
    if i not in d: r.append(i)
print(*sorted(r,key=lambda x: info.index(x) if x in info else float('inf')),sep="\n")