#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf 1000000001

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