n = int(input())
m = int(input())

p_q_lst = [ list(map(int, input().split(' '))) for i in range(m) ]


for p_q in p_q_lst:
    p = p_q[0]
    q = p_q[1]

    if p == n:
        n = q
    elif q == n:
        n = p
    
print(n)