N=int(input())

M=[input().split() for i in range(N)]

ANS=[]
BAN=set()
USE=[0]*N

for x,y in M:
    ANS.append(y)
    BAN.add(x)

for i in range(N):
    if ANS[i] in BAN:
        USE[i]=1

A=[ANS[i] for i in range(N) if USE[i]==0]
USE=set()

for a in A:
    if a in USE:
        continue
    print(a)
    USE.add(a)