N = int(input())
M = int(input())

cup = ['' for i in range(4)]
cup[N] = 'O'

for i in range(M):
  P, Q = (int(i) for i in input().split(' '))
  cup[P], cup[Q] = cup[Q], cup[P]

for i in range(len(cup)):
  if cup[i] == 'O':
    print(i)
    break