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

typedef long long Int;
#define REP(i,n) for(int (i)=0;(i)<(int)(n);++(i))

int main() {
	int N, M; cin >> N >> M;
	REP(m, M) {
		int P, Q; cin >> P >> Q;
		if (N == P) { N = Q; }
		else if (N == Q) { N = P;  }
	}
	cout << N << endl;
}