import sys
read = sys.stdin.buffer.read

_,*AB = read().decode('utf-8').split()
A = AB[::2]
B = AB[1::2]

se = set(A)
answer = []
for x in B:
    if x in se:
        continue
    se.add(x)
    answer.append(x)
    
if answer:
    print('\n'.join(map(str,answer)))