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

int main()
{
int i;
int N;
int M;
int P;
int Q;

	cin >> N;
	cin >> M;
	for( i = 0; i < M; i++ )
	{
		cin >> P;
		cin >> Q;
		if( P == N )
			N = Q;
		else if( Q == N )
			N = P;
	}

	cout << N << endl;

	return 0;
}