#include <bits/stdc++.h>
#define rep(i, a, n) for (int i = a; i < n; i++)
#define repr(i, a, n) for (int i = n - 1; i >= a; i--)
using namespace std;
using ll = long long;
using P = pair<int, int>;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);

  int n, m;
  cin >> n >> m;
  rep(i, 0, m) {
    int p, q;
    cin >> p >> q;
    if (p == n)
      n = q;
    else if (q == n)
      n = p;
  }
  cout << n << endl;
}