#include <bits/stdc++.h>
using namespace std;
typedef unsigned long long ul;
typedef signed long long ll;
ul over = 1000000007;

int main(void)
{
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed;
  int n, m;
  cin >> n >> m;
  for (int i = 0; i < m; ++i) {
    int p, q;
    cin >> p >> q;
    if (n==p) n = q;
    else if (n==q) n = p;
  }
  cout << n << endl;
  return 0;
}