#include <bits/stdc++.h>
using namespace std;
int n,m;
const int N=2000; 
struct node{
	int to,l,c; 
}; 
vector<node>G[N];
int ans; 
int vis[N];
void dfs(int u,int fa){
	vis[u]=1;
	for(auto to:G[u]){
		int v=to.to;
		int c=to.c;
		int l=to.l;
		if(vis[v]){
			continue;
		}
		ans^=c;	
		ans|=l;
		dfs(v,u);
	}
} 
int main(){
	freopen("Roads.in","r",stdin);
	freopen("Roads.out","w",stdout); 	
	srand(time(0));
	cin>>n>>m;
	for(int i=1;i<=m;i++){
		int u,v,l,c;
		cin>>u>>v>>l>>c;
		G[u].push_back({v,l,c}); 
		G[v].push_back({u,l,c});
	}
	dfs(1,0);
	cout<<ans+rand()%n;

	return 0;
}