#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<queue>
using namespace std;
int const maxn=5005,maxm=20005,inf=0x3f3f3f3f;
int n,m,hd[maxn],ct,to[maxm],nxt[maxm],w[maxm],dis[maxn],mx,ans=inf;
int son[maxn],ss,wt[maxn],wc[maxn];
bool vis[maxn],st[maxn],ed[maxn];
priority_queue<pair<int,int> >q;
void add(int x,int y,int z){to[++ct]=y; nxt[ct]=hd[x]; w[ct]=z; hd[x]=ct;}
void dijkstra()
{while(q.size())q.pop();memset(vis,0,sizeof vis);memset(dis,0x3f,sizeof dis);dis[1]=0; q.push(make_pair(0,1));
//    for(int i=1,x;i<=ss;i++)
//        if(st[x=son[i]])dis[x]=wt[x],q.push(make_pair(-dis[x],x));
//    vis[1]=1;while(q.size()){int x=q.top().second; q.pop();if(vis[x])continue; vis[x]=1;for(int i=hd[x],u;i;i=nxt[i]){if(vis[u=to[i]]||st[x]&&u==1||x==1&&ed[u])continue;
//            if(vis[u=to[i]])continue;if(dis[u]>dis[x]+w[i])dis[u]=dis[x]+w[i],q.push(make_pair(-dis[u],u));}}for(int i=1,x;i<=ss;i++)if(ed[x=son[i]])ans=min(ans,dis[x]+wc[x]);
}
int main()
{scanf("%d%d",&n,&m);int tmp=n; while(tmp)mx++,tmp/=2;for(int i=1,x,y,a,b;i<=m;i++){scanf("%d%d%d%d",&x,&y,&a,&b);add(x,y,a); add(y,x,b);if(x==1)son[++ss]=y,wt[y]=a,wc[y]=b;if(y==1)son[++ss]=x,wt[x]=b,wc[x]=a;}for(int i=0;i<mx;i++){memset(st,0,sizeof st);memset(ed,0,sizeof ed);for(int j=1;j<=ss;j++)if(son[j]&(1<<i))st[son[j]]=1;else ed[son[j]]=1;dijkstra();for(int j=1,x;j<=ss;j++)if(st[x=son[j]])st[x]=0,ed[x]=1;else if(ed[x])ed[x]=0,st[x]=1;dijkstra();}printf("%d\n",ans);return 0;
}