#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstdlib>
#include<cstring>
#include<vector>
#include<queue>
using namespace std;
int n,m,ans,maxx,from,now,pre;
struct edge{
	int to,l;
};
vector<edge>p[40050];
inline void dfs(){
	for(int i=0;i<p[now].size();i++)
	if(p[now][i].to!=pre){
		if(p[now][i].to==1){
			ans+=p[now][i].l;
			if(maxx!=0)maxx=min(maxx,ans);
			else maxx=ans;
//			cout<<ans<<endl;
			return;
		}
		else {
			ans+=p[now][i].l;
//			cout<<now<<' '<<p[now][i].l<<' '<<ans<<endl;
			int xx=pre;
			pre=now;
		    now=p[now][i].to;
		    dfs();
		    now=pre;ans-=p[now][i].l;
		    pre=xx;
		}
		
	    
	}
}

int main()
{
	freopen("both.in","r",stdin);
	freopen("both.out","w",stdout);
	cin>>n>>m;
	for(int i=1;i<=m;i++){
		int a,b,c,d;
		cin>>a>>b>>c>>d;
		p[a].push_back((edge){b,c});
    	p[b].push_back((edge){a,d});
	}
	pre=1;now=1;
	dfs();
	if(maxx==0)cout<<0-1;
	else cout<<maxx;
}