#include <bits/stdc++.h>
using namespace std;;
#define ll long long
#define ar array
#define ld long double
#define int long long
#define all(v) v.begin(), v.end()
const int N = 1e5 + 20;
const int K = 469;
const int LOG = 21;
const int INF = 1e16;
int MOD = 1e9 + 7;
template<typename T>
void chmin(T &x,T y){x = min(x, y);}
template<typename T>
void chmax(T &x,T y){x = max(x, y);}
void mm(int &x){x = (x % MOD + MOD) % MOD;};
void orz(){
int n, m;
cin>>n>>m;
vector<ar<int, 3> >g[n];
for(int i = 0;i < m;i++){
int a, b, c, d;
cin>>a>>b>>c>>d;
--a, --b, --c;
g[a].push_back({b, c, d});
g[b].push_back({a, c, d});
}
priority_queue<ar<int, 2> > pq;
pq.push({0, 0});
bool vis[n];
int dst[n];
memset(vis, 0, sizeof vis);
memset(dst, 0x3f, sizeof dst);
dst[0] = 0;
int s[m], p[m];
while(pq.size()){
auto [d, x] = pq.top();
pq.pop();
if(vis[x])continue;
vis[x] = 1;
//cout<<d<<": "<<x<<'\n';
for(auto [u, a, b]: g[x])p[a] = INF, s[a] = 0;
for(auto [u, a, b]: g[x])s[a] += b;
for(auto [u, a, b]: g[x])chmin(p[a], dst[u] + s[a]);
for(auto [u, a, b]: g[x]){
int w = min({dst[x] + b, dst[x] + s[a] - b, p[a] - b});
if(w < dst[u]){
dst[u] = w;
pq.push({-dst[u], u});
}
}
}
if(dst[n - 1] >= INF)cout<<-1;
else cout<<dst[n - 1];
}
signed main(){ios_base::sync_with_stdio(false);cin.tie(0);
int t = 1;
//cin>>t;
//t = 1;
while(t--)orz();
}
