#include <bits/stdc++.h>
#define fore(i, a, b) for (int i = (a), i##_last = (b); i < i##_last; ++i)
#define fort(i, a, b) for (int i = (a), i##_last = (b); i <= i##_last; ++i)
#define ford(i, a, b) for (int i = (a), i##_last = (b); i >= i##_last; --i)
#define fi first
#define se second
#define pb push_back
#define sz(x) ((int)(x).size())
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
using namespace std;
using ll = long long;
using ld = long double;
using ull = unsigned long long;
template<class A, class B> bool maxi(A &a, const B &b) {return (a < b) ? (a = b, true): false;};
template<class A, class B> bool mini(A &a, const B &b) {return (a > b) ? (a = b, true): false;};
typedef pair<int, int> ii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<vi> vvi;
typedef vector<vii> vvii;
template<class A, class B> ostream& operator << (ostream &outputStream, const pair<A, B> &p) {
return outputStream << '{' << p.fi << ", " << p.se << '}';
}
template<class T> ostream& operator << (ostream &outputStream, const vector<T> &v) {
outputStream << '{';
for (const T &t : v)
outputStream << t << ' ';
return outputStream << '}';
}
constexpr ll INF = 0X3F3F3F3F3F3F3F3F;
constexpr int MAX_S = 1E5 + 5;
unordered_map<int, tuple<ll, ll, vii> > g[MAX_S];
ll f[MAX_S];
int S, K;
void input() {
int u = 0, v = 0, x = 0, w = 0;
cin >> S >> K;
fort(i, 2, S)
f[i] = INF;
fort(_, 1, K) {
cin >> u >> v >> x >> w;
auto &[fu, su, eu] = g[u][x];
auto &[fv, sv, ev] = g[v][x];
fu = fv = INF;
su += w;
sv += w;
eu.emplace_back(w, v);
ev.emplace_back(w, u);
}
}
void solve() {
priority_queue<tuple<ll, int, int>, vector<tuple<ll, int, int> >, greater<tuple<ll, int, int> > > heap;
heap.emplace(0, 1, 0);
for (; !heap.empty();) {
const auto [w, u, c] = heap.top();
heap.pop();
if (c) {
auto &[fu, su, eu] = g[u][c];
if (fu != w)
continue;
for (const auto &[w, v] : eu)
if (mini(f[v], su - w + fu))
heap.emplace(f[v], v, 0);
} else {
if (f[u] != w)
continue;
for (const auto &[c, e] : g[u]) {
const auto &[fu, su, eu] = e;
for (const auto &[w, v] : eu) {
auto &[fv, sv, ev] = g[v][c];
if (mini(f[v], min((ll)w, su - w) + f[u]))
heap.emplace(f[v], v, 0);
if (mini(fv, f[u]))
heap.emplace(fv, v, c);
}
}
}
}
cout << ((f[S] < INF) ? f[S] : (-1)) << '\n';
}
int main() {
#ifdef LOCAL
freopen("input.INP", "r", stdin);
#endif // LOCAL
cin.tie(0) -> sync_with_stdio(0);
cout.tie(0);
input();
solve();
return 0;
}
