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

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