N=int(input())
A=[]
BAN={}
for i in range(N):
    a,b=input().split()
    A.append(b)
    BAN[a]=1
    
ans={}
for i in range(N):
    if A[i] not in BAN and A[i] not in ans:
        print(A[i])
        ans[A[i]]=1