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

template<typename T>
void fin(T a){
  cout<<a<<endl;
  exit(0);
}

signed main(){
    int m,n;cin>>m>>n;
    while(n--){
        int a,b;cin>>a>>b;
        if(a==m||b==m)m=a+b-m;
    }
    cout<<m<<endl;
}