#include <bits/stdc++.h>
using namespace std;
int main() {
	int N, M;
	cin >> N >> M;
	int P, Q;
	for(int i = 0; i < M; i++) {
		cin >> P >> Q;
		if(N == P) N = Q;
		else if(N == Q) N = P;
	}
	cout << N << endl;
	return 0;
}