#include <bits/stdc++.h>
using namespace std;
constexpr long long mod = 1000000007;
const long long INF = mod * mod;
const long double eps = 1e-12;
const long double pi = acosl(-1.0);
long long mod_pow(long long x, long long n, long long m = mod) {
  long long res = 1;
  while (n) {
    if (n & 1) res = res * x % m;
    x = x * x % m;
    n >>= 1;
  }
  return res;
}
struct modint {
  long long n;
  modint() : n(0) { ; }
  modint(long long m) : n(m) {
    if (n >= mod)
      n %= mod;
    else if (n < 0)
      n = (n % mod + mod) % mod;
  }
  operator int() { return n; }
};
bool operator==(modint a, modint b) { return a.n == b.n; }
modint operator+=(modint& a, modint b) {
  a.n += b.n;
  if (a.n >= mod) a.n -= mod;
  return a;
}
modint operator-=(modint& a, modint b) {
  a.n -= b.n;
  if (a.n < 0) a.n += mod;
  return a;
}
modint operator*=(modint& a, modint b) {
  a.n = ((long long)a.n * b.n) % mod;
  return a;
}
modint operator+(modint a, modint b) { return a += b; }
modint operator-(modint a, modint b) { return a -= b; }
modint operator*(modint a, modint b) { return a *= b; }
modint operator^(modint a, long long n) {
  if (n == 0) return modint(1);
  modint res = (a * a) ^ (n / 2);
  if (n % 2) res = res * a;
  return res;
}
long long inv(long long a, long long p) {
  return (a == 1 ? 1 : (1 - p * inv(p % a, a)) / a + p);
}
modint operator/(modint a, modint b) { return a * modint(inv(b, mod)); }
int max_n;
const int mn = 100000;
struct edge {
  int to, cap;
  long long cost;
  int rev;
};
vector<edge> G[mn];
pair<int, int> par[mn];
long long dist[mn];
void add_edge(int from, int to, int cap, long long cost) {
  G[from].push_back({to, cap, cost, (int)G[to].size()});
  G[to].push_back({from, 0, -cost, (int)G[from].size() - 1});
  max_n = max({max_n, from + 1, to + 1});
}
void add_edge2(int from, int to, int cap, long long cost) {
  G[from].push_back({to, cap, cost, -1});
  max_n = max({max_n, from + 1, to + 1});
}
pair<long long, long long> minimum_road(int s, int t) {
  fill(par, par + max_n, pair<int, int>{-1, -1});
  fill(dist, dist + max_n, INF);
  dist[s] = 0;
  priority_queue<pair<long long, long long>, vector<pair<long long, long long>>,
                 greater<pair<long long, long long>>>
      q;
  q.push({0, s});
  while (!q.empty()) {
    pair<long long, long long> p = q.top();
    q.pop();
    int id = p.second;
    if (id == t) continue;
    if (p.first > dist[id]) continue;
    for (int j = 0; j < G[id].size(); j++) {
      if (G[id][j].cap > 0) {
        int to = G[id][j].to;
        long long nd = p.first + G[id][j].cost;
        if (nd < dist[to]) {
          dist[to] = nd;
          par[to] = {id, j};
          q.push({dist[to], to});
        }
      }
    }
  }
  int cur = t;
  int f = mod;
  while (cur != s) {
    int p = par[cur].first, j = par[cur].second;
    if (p < 0) return {-1, -1};
    f = min(f, G[p][j].cap);
    cur = p;
  }
  cur = t;
  while (cur != s) {
    int p = par[cur].first, j = par[cur].second;
    if (p < 0) return {-1, -1};
    G[p][j].cap -= f;
    if (G[p][j].rev >= 0) {
      G[cur][G[p][j].rev].cap += f;
    }
    cur = p;
  }
  return {dist[t], f};
}
long long minimum_cost_flow(int s, int t, int k = mod) {
  long long ret = 0;
  for (int i = 0; i < k; i++) {
    pair<long long, long long> z = minimum_road(s, t);
    if (z.first < 0) return ret;
    if (k - i <= z.second) {
      ret += z.first * (k - i);
      break;
    }
    i += z.second - 1;
    ret += z.first * z.second;
  }
  return ret;
}
void solve() {
  int n, m;
  cin >> n >> m;
  vector<int> d(n + 2 * m);
  for (int i = 0; i < m; i++) {
    int a, b, c, f;
    cin >> a >> b >> c >> f;
    a--;
    b--;
    int le = n + 2 * i;
    int ri = n + 2 * i + 1;
    add_edge(a, le, mod, 1);
    add_edge(le, a, f, 1);
    add_edge(ri, b, mod, 1);
    add_edge(b, ri, f, 1);
    add_edge(le, ri, c, 0);
    add_edge(le, ri, mod, 2);
    d[a] += -f;
    d[le] += f;
    d[ri] += -f;
    d[b] += f;
  }
  int sum = 0;
  int s = n + 2 * m;
  int t = s + 1;
  int sum2 = 0;
  int S = t + 1;
  int T = S + 1;
  for (int i = 0; i < n + 2 * m; i++) {
    if (d[i] > 0) {
      sum += abs(d[i]);
      add_edge(s, i, d[i], 0);
    } else if (d[i] < 0) {
      sum2 += abs(d[i]);
      add_edge(i, t, -d[i], 0);
    }
  }
  max_n = T + 1;
  add_edge(n - 1, 0, mod, 0);
  int ans = 0;
  ans += minimum_cost_flow(s, t, sum);
  cout << ans / 2 << "\n";
}
signed main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  solve();
  return 0;
}
