# -*- coding: utf-8 -*-

n = int(input())
m = int(input())
p = [0] * m
q = [0] * m
for i in range(m):
    p[i], q[i] = map(int,input().split())

for i in range(m):
    if p[i] == n:
        n = q[i]
    elif q[i] == n:
        n = p[i]

print(n)