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

int main() {
	int cup[3]={0};
	int N,M,P,Q;
	cin>>N>>M;
	cup[N-1]=1;
	for(int i=0;i<M;i++){
		cin>>P>>Q;
		if(cup[P-1]){
			cup[P-1]=0;
			cup[Q-1]=1;
		}else if(cup[Q-1]){
			cup[Q-1]=0;
			cup[P-1]=1;
		}
	}
	if(cup[0]){
		cout<<1<<endl;
	}else if(cup[1]){
		cout<<2<<endl;
	}else if(cup[2]){
		cout<<3<<endl;
	}
	return 0;
}