n = int(input())
ab = [input().split() for _ in range(n)]
B = set()
A = set()
for a, b in ab:
    A.add(a)
    B.add(b)
    
for a in A:
    if a in B:
        B.remove(a)
        
for a, b in ab:
    if b in B:
        print(b)
        B.remove(b)