#include using namespace std; typedef long long ll; #define pb(x) push_back(x) #define mp(a, b) make_pair(a, b) #define all(x) x.begin(), x.end() #define rall(x) x.rbegin(), x.rend() #define lscan(x) scanf("%I64d", &x) #define lprint(x) printf("%I64d", x) #define rep(i, n) for (ll i = 0; i < (n); i++) #define rep2(i, n) for (ll i = n - 1; i >= 0; i--) template using rque = priority_queue, greater>; const ll mod = 998244353; ll gcd(ll a, ll b) { ll c = a % b; while (c != 0) { a = b; b = c; c = a % b; } return b; } long long extGCD(long long a, long long b, long long &x, long long &y) { if (b == 0) { x = 1; y = 0; return a; } long long d = extGCD(b, a % b, y, x); y -= a / b * x; return d; } struct UnionFind { vector data; UnionFind(int sz) { data.assign(sz, -1); } bool unite(int x, int y) { x = find(x), y = find(y); if (x == y) return (false); if (data[x] > data[y]) swap(x, y); data[x] += data[y]; data[y] = x; return (true); } int find(int k) { if (data[k] < 0) return (k); return (data[k] = find(data[k])); } ll size(int k) { return (-data[find(k)]); } }; ll M = 1000000007; vector fac(2000011); //n!(mod M) vector ifac(2000011); //k!^{M-2} (mod M) ll mpow(ll x, ll n) { ll ans = 1; while (n != 0) { if (n & 1) ans = ans * x % M; x = x * x % M; n = n >> 1; } return ans; } ll mpow2(ll x, ll n, ll mod) { ll ans = 1; while (n != 0) { if (n & 1) ans = ans * x % mod; x = x * x % mod; n = n >> 1; } return ans; } void setcomb() { fac[0] = 1; ifac[0] = 1; for (ll i = 0; i < 2000010; i++) { fac[i + 1] = fac[i] * (i + 1) % M; // n!(mod M) } ifac[2000010] = mpow(fac[2000010], M - 2); for (ll i = 2000010; i > 0; i--) { ifac[i - 1] = ifac[i] * i % M; } } ll comb(ll a, ll b) { if (a == 0 && b == 0) return 1; if (a < b || a < 0) return 0; ll tmp = ifac[a - b] * ifac[b] % M; return tmp * fac[a] % M; } ll perm(ll a, ll b) { if (a == 0 && b == 0) return 1; if (a < b || a < 0) return 0; return fac[a] * ifac[a - b] % M; } long long modinv(long long a) { long long b = M, u = 1, v = 0; while (b) { long long t = a / b; a -= t * b; swap(a, b); u -= t * v; swap(u, v); } u %= M; if (u < 0) u += M; return u; } ll modinv2(ll a, ll mod) { ll b = mod, u = 1, v = 0; while (b) { ll t = a / b; a -= t * b; swap(a, b); u -= t * v; swap(u, v); } u %= mod; if (u < 0) u += mod; return u; } template struct ModInt { int x; ModInt() : x(0) {} ModInt(int64_t y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {} ModInt &operator+=(const ModInt &p) { if ((x += p.x) >= mod) x -= mod; return *this; } ModInt &operator-=(const ModInt &p) { if ((x += mod - p.x) >= mod) x -= mod; return *this; } ModInt &operator*=(const ModInt &p) { x = (int)(1LL * x * p.x % mod); return *this; } ModInt &operator/=(const ModInt &p) { *this *= p.inverse(); return *this; } ModInt operator-() const { return ModInt(-x); } ModInt operator+(const ModInt &p) const { return ModInt(*this) += p; } ModInt operator-(const ModInt &p) const { return ModInt(*this) -= p; } ModInt operator*(const ModInt &p) const { return ModInt(*this) *= p; } ModInt operator/(const ModInt &p) const { return ModInt(*this) /= p; } bool operator==(const ModInt &p) const { return x == p.x; } bool operator!=(const ModInt &p) const { return x != p.x; } ModInt inverse() const { int a = x, b = mod, u = 1, v = 0, t; while (b > 0) { t = a / b; swap(a -= t * b, b); swap(u -= t * v, v); } return ModInt(u); } ModInt pow(int64_t n) const { ModInt ret(1), mul(x); while (n > 0) { if (n & 1) ret *= mul; mul *= mul; n >>= 1; } return ret; } friend ostream &operator<<(ostream &os, const ModInt &p) { return os << p.x; } friend istream &operator>>(istream &is, ModInt &a) { int64_t t; is >> t; a = ModInt(t); return (is); } static int get_mod() { return mod; } }; using mint = ModInt; typedef vector> Matrix; Matrix mul(Matrix a, Matrix b) { int i, j, k; mint t; int n = a.size(), m = b[0].size(), l = a[0].size(); Matrix c(n, vector(m)); for (i = 0; i < n; i++) { for (j = 0; j < m; j++) { t = 0; for (k = 0; k < l; k++) t += a[i][k] * b[k][j]; c[i][j] = t; } } return c; } Matrix mat_pow(Matrix x, ll n) { ll k = x.size(); Matrix ans(k, vector(k, 0)); for (int i = 0; i < k; i++) ans[i][i] = 1; while (n != 0) { if (n & 1) ans = mul(ans, x); x = mul(x, x); n = n >> 1; } return ans; } template struct PrimalDual { const cost_t INF; bool neg_edge; 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()), neg_edge(false) {} 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}); if(cost < 0) neg_edge = 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; if(neg_edge){ potential.assign(V, INF); potential[s] = 0; while (1) { bool update = false; for (int i = 0; i < V; i++) { if (potential[i] != INF) { for (int j = 0; j < graph[i].size(); j++) { edge &e = graph[i][j]; cost_t nextCost = potential[i] + e.cost; if (e.cap > 0 && potential[e.to] > nextCost) { potential[e.to] = nextCost; update = true; } } } } if (!update) break; } } else 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; } vector,int>> get_edges() { vector, int>> E; 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]; E.push_back(mp(mp(i, e.to), rev_e.cap)); } } return E; } 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; } } } }; int main() { ll n, m; cin >> n >> m; PrimalDual mcf(n+m*2); ll u, v, c, d; rep(i, m){ cin >> u >> v >> c >> d; u--, v--; mcf.add_edge(u, n + i, 2, 0); mcf.add_edge(v, n + i, 2, 0); mcf.add_edge(n + i, n + i + m, 1, c); mcf.add_edge(n + i, n + i + m, 1, d); mcf.add_edge(n + i + m, u, 2, 0); mcf.add_edge(n + i + m, v, 2, 0); } cout << mcf.min_cost_flow(0, n-1, 2) << endl; }