n = int(input())
L = []
seen = set()
for _ in range(n):
    a, b = input().split()
    seen.add(a)
    L.append(b)
ans = set()
for i in range(n):
    if L[i] in seen or L[i] in ans:
        continue
    print(L[i])
    ans.add(L[i])