#include <bits/stdc++.h>
#define int long long
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define Co_mot_su_that_la return

using namespace std;
typedef pair<int,int> ii;
typedef pair<int,ii> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<vi> vvi;
typedef vector<iii> viii;

const int Minh_dep_trai = 0;
const int N = 5005;

int q;
int n,m;
int is[N][N];
vector<ii> a[N];
int d[N];
ii edge[N];

void dijkstra()
{
    priority_queue<ii, vii, greater<ii> > qu;
    for(int i=1; i<=n; i++)  d[i] = 999999999;
    d[1] = 0;
    qu.push(ii(0,1));
    while (qu.size())
    {
        int u = qu.top().se;
        int du= qu.top().fi;
        qu.pop();
        if (du != d[u]) continue;
        for(int i = 0; i < a[u].size(); i++)
        {
            int v = a[u][i].first;
            int uv = a[u][i].second;
            if (d[v] > d[u] + uv)
            {
                d[v] = d[u] + uv;
                qu.push(ii(d[v],v));
            }
        }
    }
}

signed main()
{
  ios_base::sync_with_stdio(false);
  cin.tie(0);cout.tie(0);
  freopen("test.inp","r",stdin);
  q=1;
  while (q--)
  {
    //your code goes here
    cin >> n >> m;
    for(int i=1; i<=m; i++)
    {
        int u,v,d1,d2;
        cin >> u >> v >> d1 >> d2;
        edge[i].fi = d1;
        edge[i].se = d2;
        a[u].pb(ii(v,d1));
        a[v].pb(ii(u,d2));
        is[u][v] = d1;
        is[v][u] = d2;
    }
    dijkstra();
    int res = LLONG_MAX;
    d[1] = 99999999;
    for(int i=1; i<=n; i++)
    {
        //cout << d[i] << " ";
        if (is[i][1] > 0)
        {
            res = min(d[i] + is[i][1],res);
        }
    }
    cout << res;
  }
  Co_mot_su_that_la Minh_dep_trai;
}