#include <iostream>
using namespace std;

int main() {

  int N,M;
  int NowPosition;

  cin >> N >> M;
  NowPosition = N;

  int P[M];
  int Q[M];

  for(int i = 0; i < M; i++){
    cin >> P[i] >> Q[i];
  }

  for(int i =0; i < M; i++){
    if(NowPosition == P[i] || NowPosition == Q[i]){
      if(NowPosition == P[i]){
        NowPosition = Q[i];
      }
      else{
        NowPosition = P[i];
      }
    }
  }

  cout << NowPosition << endl;

  return 0;

}