#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (n); ++i)

int main(void)
{
  int n, m;
  cin >> n >> m;
  vector<int> p(m), q(m);
  rep(i, m)
  {
    cin >> p[i] >> q[i];
    if (p[i] == n)
    {
      n = q[i];
    }
  }
  cout << n << '\n';
  return 0;
}