#include <bits/stdc++.h>
#define FOR(i,a,b) for(int i = (a); i < (b); ++i)
using namespace std;

int main() {
	int n, m;
	cin >> n >> m;
	FOR(i, 0, m) {
		int p, q;
		cin >> p >> q;
		if (n == p || n == q) n = (n != p) ? p : q;
	}
	cout << n << endl;
	return 0;
}