#include <bits/stdc++.h>
using namespace std;
const int inf = 0x3f3f3f3f;
namespace mcmf {
const int MAX = 1000010;
const long long INF = 1LL << 60;
long long cap[MAX], flow[MAX], cost[MAX], dis[MAX];
int n, m, s, t, Q[10000010], adj[MAX], link[MAX], last[MAX], from[MAX],
    visited[MAX];
void init(int nodes, int source, int sink) {
  m = 0, n = nodes, s = source, t = sink;
  for (int i = 0; i <= n; i++) last[i] = -1;
}
void addEdge(int u, int v, long long c, long long w) {
  adj[m] = v, cap[m] = c, flow[m] = 0, cost[m] = +w, link[m] = last[u],
  last[u] = m++;
  adj[m] = u, cap[m] = 0, flow[m] = 0, cost[m] = -w, link[m] = last[v],
  last[v] = m++;
}
bool spfa() {
  int i, j, x, f = 0, l = 0;
  for (i = 0; i <= n; i++) visited[i] = 0, dis[i] = INF;
  dis[s] = 0, Q[l++] = s;
  while (f < l) {
    i = Q[f++];
    for (j = last[i]; j != -1; j = link[j]) {
      if (flow[j] < cap[j]) {
        x = adj[j];
        if (dis[x] > dis[i] + cost[j]) {
          dis[x] = dis[i] + cost[j], from[x] = j;
          if (!visited[x]) {
            visited[x] = 1;
            if (f && rand() & 7)
              Q[--f] = x;
            else
              Q[l++] = x;
          }
        }
      }
    }
    visited[i] = 0;
  }
  return (dis[t] != INF);
}
pair<long long, long long> maxFlow() {
  int i, j;
  long long mincost = 0, maxflow = 0;
  while (spfa()) {
    long long aug = INF;
    for (i = t, j = from[i]; i != s; i = adj[j ^ 1], j = from[i]) {
      aug = min(aug, cap[j] - flow[j]);
    }
    for (i = t, j = from[i]; i != s; i = adj[j ^ 1], j = from[i]) {
      flow[j] += aug, flow[j ^ 1] -= aug;
    }
    maxflow += aug, mincost += aug * dis[t];
  }
  return make_pair(maxflow, mincost);
}
}  // namespace mcmf
using namespace mcmf;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  ;
  int n, m;
  cin >> n >> m;
  int src = 0, snk = n + n + 1;
  init(snk + 7, src, snk);
  long long res = 0;
  while (m--) {
    int u, v, c, f;
    cin >> u >> v >> c >> f;
    res += f;
    if (c >= f) {
      addEdge(u, v + n, f, -1);
      addEdge(u, v + n, c - f, 1);
      addEdge(u, v + n, inf, 2);
    } else {
      addEdge(u, v + n, c, -1);
      addEdge(u, v + n, f - c, 0);
      addEdge(u, v + n, inf, 2);
    }
  }
  for (int i = 1; i <= n; ++i) {
    if (i != n) addEdge(src, i, inf, 0);
    if (i > 1 and i < n) addEdge(i, i + n, inf, 0);
    if (i != 1) addEdge(i + n, snk, inf, 0);
  }
  addEdge(1, n + n, inf, 0);
  auto fl = maxFlow();
  res += fl.second;
  cout << res << "\n";
  return 0;
}
