#include <iostream>
using namespace std;
 
int main(){
	int N, M;
	cin >> N >> M;
	int cups[N];
	for(int i = 0; i < N; i++){
		cups[i] = i;
	}
	for(int i = 0; i < M; i++){
		int P, Q;
		cin >> P >> Q;
		int tmp = cups[P - 1];
		cups[P - 1] = cups[Q - 1];
		cups[Q - 1] = tmp;
	}
	for(int i = 0; i < N; i++){
		if(cups[i] == 0){
			cout << i + 1 << endl;
			return 0;
		}
	}
}