n=int(input())
fir=[]
sec=[]
for i in range(n):
    q,r=map(str,input().split())
    fir.append(q)
    sec.append(r)
ans=[]
for i in range(n):
    if sec[i] not in fir:
        if sec[i] not in ans:
            ans.append(sec[i])
for i in range(len(ans)):
    print(ans[i])