#include using namespace std; /* #include using namespace atcoder; */ #define all(hoge) (hoge).begin(), (hoge).end() #define en '\n' using ll = long long; using ull = unsigned long long; #define rep(i, m, n) for(ll i = (ll)(m); i < (ll)(n); ++i) #define rep2(i, m, n) for(ll i = (ll)(n)-1; i >= (ll)(m); --i) #define REP(i, n) rep(i, 0, n) #define REP2(i, n) rep2(i, 0, n) template using vec = vector; template using vvec = vector>; typedef pair P; using tp = tuple; constexpr long long INF = 1LL << 60; constexpr int INF_INT = 1 << 25; //constexpr long long MOD = (ll)1e9 + 7; constexpr long long MOD = 998244353LL; using ld = long double; static const ld pi = 3.141592653589793L; using Array = vector; using Matrix = vector; /* #pragma GCC target("avx2") #pragma GCC optimize("O3") #pragma GCC optimize("unroll-loops") */ template inline bool chmin(T &a, T b) { if(a > b) { a = b; return true; } return false; } template inline bool chmax(T &a, T b) { if(a < b) { a = b; return true; } return false; } template struct PrimalDual { const cost_t INF; struct edge { int to; flow_t cap; cost_t cost; int rev; bool isrev; }; vector> graph; vector potential, min_cost; vector prevv, preve; PrimalDual(int V) : graph(V), INF(numeric_limits::max()) {} void add_edge(int from, int to, flow_t cap, cost_t cost) { graph[from].emplace_back((edge){to, cap, cost, (int)graph[to].size(), false}); graph[to].emplace_back((edge){from, 0, -cost, (int)graph[from].size() - 1, true}); } cost_t min_cost_flow(int s, int t, flow_t f) { int V = (int)graph.size(); cost_t ret = 0; using Pi = pair; priority_queue, greater> que; potential.assign(V, 0); preve.assign(V, -1); prevv.assign(V, -1); while(f > 0) { min_cost.assign(V, INF); que.emplace(0, s); min_cost[s] = 0; while(!que.empty()) { Pi p = que.top(); que.pop(); if(min_cost[p.second] < p.first) continue; for(int i = 0; i < graph[p.second].size(); i++) { edge &e = graph[p.second][i]; cost_t nextCost = min_cost[p.second] + e.cost + potential[p.second] - potential[e.to]; if(e.cap > 0 && min_cost[e.to] > nextCost) { min_cost[e.to] = nextCost; prevv[e.to] = p.second, preve[e.to] = i; que.emplace(min_cost[e.to], e.to); } } } if(min_cost[t] == INF) return -1; for(int v = 0; v < V; v++) potential[v] += min_cost[v]; flow_t addflow = f; for(int v = t; v != s; v = prevv[v]) { addflow = min(addflow, graph[prevv[v]][preve[v]].cap); } f -= addflow; ret += addflow * potential[t]; for(int v = t; v != s; v = prevv[v]) { edge &e = graph[prevv[v]][preve[v]]; e.cap -= addflow; graph[v][e.rev].cap += addflow; } } return ret; } void output() { for(int i = 0; i < graph.size(); i++) { for(auto &e : graph[i]) { if(e.isrev) continue; auto &rev_e = graph[e.to][e.rev]; cout << i << "->" << e.to << " (flow: " << rev_e.cap << "/" << rev_e.cap + e.cap << ")" << endl; } } } }; void solve() { int n, m; cin >> n >> m; PrimalDual pd(n); REP(i, m) { int u, v, c, d; cin >> u >> v >> c >> d; u--; v--; pd.add_edge(u, v, 1, c); pd.add_edge(v, u, 1, c); pd.add_edge(u, v, 1, d); pd.add_edge(v, u, 1, d); } auto ans = pd.min_cost_flow(0, n - 1, 2); cout << ans << en; } int main() { ios::sync_with_stdio(false); cin.tie(0); cout.tie(0); /* ll t; cin >> t; REP(i, t - 1) { solve(); }*/ solve(); return 0; }