N=int(input())
A=[]
B=[]
C=set()

for i in range(N):
    a,b=input().split()
    A.append(a)

    if b not in C:
        B.append(b)
        C.add(b)

for a in A:
    if a in C:
        B.remove(a)
        C.remove(a)

for b in B:
    print(b)