#include <bits/stdc++.h>
using namespace std;

int main(){
  int n,m,ans;cin>>n>>m;
  ans=n;
  vector<int> p(m),q(m);
  for(int i=0;i<m;i++)cin>>p[i]>>q[i];
  for(int i=0;i<m;i++){
    if(ans==p[i])ans=q[i];
    else if(ans==q[i])ans=p[i];
  }
  cout<<ans<<endl;
}