# import sys; input = sys.stdin.buffer.readline
# sys.setrecursionlimit(10**7)
from collections import defaultdict
con = 10 ** 9 + 7; INF = float("inf")

def getlist():
	return list(map(int, input().split()))

#処理内容
def main():
	N = int(input())
	D = defaultdict(int)
	Blist = []
	for i in range(N):
		A, B = list(input().split())
		D[A] = 1
		Blist.append(B)

	check = defaultdict(int)
	for i in Blist:
		if D[i] == 0 and check[i] == 0:
			print(i)
			check[i] = 1

if __name__ == '__main__':
	main()