#include <algorithm>
#include <iostream>
#include <string>
#include <vector>
#include <stack>
#include <cmath>
#define REP(i,n) for (int i=0;i<(n);i++)

using namespace std;

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

	REP(i, M){
		cin >> P >> Q;
		if (N == P){ 
			N = Q; 
		}
		else if (N == Q){
			N = P;
		}
	}

	cout << N << endl;
	return 0;
}