#include <iostream>

using namespace std;

int N, M, P, Q;

int main() {
	cin >> N >> M;
	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;
}