#include <iostream>

using namespace std;

int main(int argc, const char* argv[])
{
	int N, M;
	cin >> N >> M;
	for (int i = 0; i < M; i++) {
		int P, Q;
		cin >> P >> Q;
		if (P == N)
			N = Q;
		else if (Q == N)
			N = P;
	}
	cout << N << endl;
	return 0;
}