#include<iostream>
using namespace std;
int main(void)
{
	int n, m, p, q;
	cin >> n >> m;
	int ans = n;
	for (int i = 0; i < m; i++){
		cin >> p >> q;
		if (ans == p) ans = q;
		else if (ans == q) ans = p;
	}
	cout << ans << endl;
	return 0;
}