N = int(input())
D = dict()
A, B = [None] * N, [None] * N
for i in range(N):
    A[i], B[i] = input().split()
    D[A[i]] = False
    
S = set()
for i in range(N):
    if B[i] not in D and B[i] not in S:
        print(B[i])
        S.add(B[i])