#include<iostream>


using namespace std;


int main(){
	int N,M,P,Q;

	cin >>N;
	cin >>M;

	for(int i=0; i < M; i++){
		cin >> P >> Q;
		if(P == N)
			N = Q;
		else if(Q == N)
			N = P;
	}

	cout << N << endl;

	return 0;
}