#!/usr/bin/python
# -*- coding: utf-8 -*-

#A, B = map(int, raw_input().split())
ans = int(raw_input())
N = int(raw_input())
tmp = [""]

for i in xrange(N):
       	arys = map(int, raw_input().split())
       	if ans in arys:
       		tmp[0] = ans
       		ans = list(set(arys) - set(tmp))[0]
print ans