#include using namespace std; using ll = long long; static const ll INF = 1e18; // 最小費用流 struct edge { int to; ll cap, cost; int rev; }; vector h, d; // ポテンシャル, 最短距離 vector prevv, preve; // 直前の頂点と辺 void add_edge(vector> &G, int from, int to, ll cap, ll cost) { G[from].emplace_back((edge) {to, cap, cost, (int) G[to].size()}); G[to].emplace_back((edge) {from, 0, -cost, (int) G[from].size() - 1}); } // sからtへの流量fの最小費用流(流せない場合は-1) ll min_cost_flow(vector> &G, int s, int t, ll f) { ll res = 0; h.assign(G.size(), 0); prevv.assign(G.size(), 0); preve.assign(G.size(), 0); while (f > 0) { priority_queue, vector>, greater>> pq; d.assign(G.size(), INF); d[s] = 0; pq.push(make_pair(0, s)); while (!pq.empty()) { pair p = pq.top(); pq.pop(); int v = p.second; if (d[v] < p.first) continue; for (int i = 0; i < G[v].size(); i++) { edge &e = G[v][i]; if (e.cap > 0 && d[e.to] > d[v] + e.cost + h[v] - h[e.to]) { d[e.to] = d[v] + e.cost + h[v] - h[e.to]; prevv[e.to] = v; preve[e.to] = i; pq.push(make_pair(d[e.to], e.to)); } } } if (d[t] == INF) return -1; for (int i = 0; i < G.size(); i++) h[i] += d[i]; // s-t間最短路に流す int nowf = f; for (int i = t; i != s; i = prevv[i]) { nowf = min(nowf, G[prevv[i]][preve[i]].cap); } f -= nowf; res += nowf * h[t]; for (int i = t; i != s; i = prevv[i]) { edge &e = G[prevv[i]][preve[i]]; e.cap -= nowf; G[i][e.rev].cap += nowf; } } return res; } int main() { ll n, m; cin >> n >> m; vector> G(n); for (int i = 0; i < m; i++) { ll u, v, c, d; cin >> u >> v >> c >> d; u--; v--; add_edge(G, u, v, 1, c); add_edge(G, u, v, 1, d); add_edge(G, v, u, 1, c); add_edge(G, v, u, 1, d); } cout << min_cost_flow(G, 0, n - 1, 2) << '\n'; }