#include<cstdio>
#include <iostream>
#include<algorithm>
#include<string>
#include<queue>
#include<vector>
#include<functional>
#include<cmath>
#include<map>
#include<stack>
#include<set>
#include<numeric>

using namespace std;
typedef long long ll;
typedef pair<ll, ll> Pr;

int N, M;

int main()
{
	cin >> N >> M;
	int mark = N;

	for (int i = 0; i < M; i++) {
		int P, Q;
		cin >> P >> Q;
		if (P == mark)mark = Q;
		else if (Q == mark)mark = P;
	}
	cout << mark << endl;
	return 0;
}