//@formatter:off #include #define rep(i,n) for (int i = 0; i < int(n); ++i) #define rrep(i,n) for (int i = int(n)-1; i >= 0; i--) #define rep2(i,s,n) for (int i = int(s); i < int(n); ++i) #define all(a) a.begin(),a.end() #define rall(a) a.rbegin(),a.rend() #define pb push_back #define eb emplace_back #define vi vector #define vvi vector> #define vl vector #define vvl vector> #define vd vector #define vvd vector> #define vs vector #define vc vector #define vvc vector> #define vb vector #define vvb vector> #define vp vector

#define vvp vector> using namespace std; using ll = long long; using P = pair; using LP = pair; template istream& operator>>(istream &is,pair &p) { return is >> p.first >> p.second; } template ostream& operator<<(ostream &os,const pair &p) { return os<<'{'< istream& operator>>(istream &is,vector &v) { for(T &t:v){is>>t;} return is; } template ostream& operator<<(ostream &os,const vector &v) { os<<'[';rep(i,v.size())os< void fin(T a) { cout << a << endl; exit(0); } template bool chmin(T& a,T b) {if(a > b){a = b; return true;} return false;} template bool chmax(T& a,T b) {if(a < b){a = b; return true;} return false;} const int inf = 1001001001; const ll linf = 1001001001001001001; //@formatter:on template class Mincostflow { using TP = pair; struct edge { int to, cap, rev; T cost; edge(int to, int cap, T cost, int rev) : to(to), cap(cap), cost(cost), rev(rev) {} }; T tinf; int n; vector> G; vector pot, dist; vi prevv, preve; // potential void tinf_init(int x) { tinf = inf; } void tinf_init(ll x) { tinf = linf; } public: explicit Mincostflow(int n) : n(n), G(n), pot(n), dist(n), prevv(n), preve(n) { T x = 0; tinf_init(x); } void add_edge(int from, int to, T cap, int cost) { G[from].eb(to, cap, cost, G[to].size()); G[to].eb(from, 0, -cost, G[from].size() - 1); } // return -1 if impossible // this must not be called more than once T min_cost_flow(int s, int t, int f) { T res = 0; pot.assign(n, 0); while (f > 0) { // use dijkstra to update pot priority_queue, greater> q; dist.assign(n, tinf); dist[s] = 0; q.emplace(0, s); while (!q.empty()) { T np = q.top().first; int v = q.top().second; q.pop(); if (dist[v] < np) continue; rep(i, G[v].size()) { edge &e = G[v][i]; if (e.cap > 0 && dist[e.to] > dist[v] + e.cost + pot[v] - pot[e.to]) { dist[e.to] = dist[v] + e.cost + pot[v] - pot[e.to]; prevv[e.to] = v; preve[e.to] = i; q.emplace(dist[e.to], e.to); } } } if (dist[t] == tinf) return -1; rep(i, n) pot[i] += dist[i]; int d = f; for (int v = t; v != s; v = prevv[v]) { chmin(d, G[prevv[v]][preve[v]].cap); } f -= d; res += d * pot[t]; for (int v = t; v != s; v = prevv[v]) { edge &e = G[prevv[v]][preve[v]]; e.cap -= d; G[v][e.rev].cap += d; } } return res; }; }; int main() { ios::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr); int n, m; cin >> n >> m; Mincostflow fl(n); rep(i, m) { int u, v, c, d; cin >> u >> v >> c >> d; u--; v--; fl.add_edge(u, v, 1, c); fl.add_edge(v, u, 1, c); fl.add_edge(u, v, 1, d); fl.add_edge(v, u, 1, d); } cout << fl.min_cost_flow(0, n - 1, 2) << endl; }