import sys,collections,math,random;sys.setrecursionlimit(10**7)
def Is(): return [int(x) for x in sys.stdin.readline().split()]
def Ss(): return sys.stdin.readline().split()
def I(): return int(sys.stdin.readline())
def S(): return input()

N = I()
set_a = set()
set_b = set()
for i in range(N):
    a,b = Ss()
    set_a.add(a)
    set_b.add(b)
for e in list(set_b - set_a):
    print(e)