#include <cstdio>
#include <stdio.h>
#include <stdbool.h>
#include <iostream>
#include <map>
#include <vector>
#include <climits>
#include <stack>
#include <string>
#include <queue>
#include <algorithm>
#include <set>
#include <unordered_set>
#include <unordered_map>
#include <cmath>
#include <cctype>
#include <bitset>
#include <iomanip>
#include <cstring>
#include <numeric>
#include <cassert>
#include <random>
#include <chrono>
#include <fstream>
using namespace std;
#define int long long
#define pii pair<int, int>
#define mp make_pair
#define pb push_back
#define fi first
#define se second
struct trio{
int to, t, c;
};
int32_t main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n, m, a, b, c, d;
cin>>n>>m;
vector<vector<trio> > graph(n+1);
while (m--){
cin>>a>>b>>c>>d;
graph[a].pb({b, c, d});
graph[b].pb({a, c, d});
}
vector<int> dj(n+1, LLONG_MAX/2);
priority_queue<pii, vector<pii>, greater<pii> > pq;
pq.push(mp(0, 1));
while (pq.size()){
int d=pq.top().fi, node=pq.top().se;
pq.pop();
if (d>=dj[node])continue;
dj[node]=d;
map<int, int> m;
for (auto num:graph[node])m[num.t]+=num.c;
for (auto num:graph[node]){
int mn=min(num.c, m[num.t]-num.c);
for (auto c:m)mn=min(mn, num.c+c.se);
pq.push(mp(d+mn, num.to));
}
}
cout<<(dj[n]==LLONG_MAX/2?-1:dj[n]);
}
