n = int(input())
ans = [[],[]]
s = 0
for a in range(n):
    cheat, p = input().split()
    if p not in ans[0]:
        ans[0].append(p)
        ans[1].append(0)
    if cheat not in ans[0]:
        ans[0].append(cheat)
        ans[1].append(-1)
    else:
        index = ans[0].index(cheat)
        ans[1][index] = -1

for a in range(len(ans[1])):
    if ans[1][a] == 0:
        print(ans[0][a])