// includes
#include <bits/stdc++.h>

// macros
#define ll long long int
#define pb emplace_back
#define mk make_pair
#define pq priority_queue
#define FOR(i, a, b) for(int i=(a);i<(b);++i)
#define rep(i, n) FOR(i, 0, n)
#define rrep(i, n) for(int i=((int)(n)-1);i>=0;i--)
#define irep(itr, st) for(auto itr = (st).begin(); itr != (st).end(); ++itr)
#define irrep(itr, st) for(auto itr = (st).rbegin(); itr != (st).rend(); ++itr)
#define vrep(v, i) for(int i = 0; i < (v).size(); i++)
#define all(x) (x).begin(),(x).end()
#define sz(x) ((int)(x).size())
#define UNIQUE(v) v.erase(unique(v.begin(), v.end()), v.end())
#define FI first
#define SE second
#define dump(a, n) for(int i = 0; i < n; i++)cout << a[i] << "\n "[i + 1 != n];
#define dump2(a, n, m) for(int i = 0; i < n; i++)for(int j = 0; j < m; j++)cout << a[i][j] << "\n "[j + 1 != m];
#define bit(n) (1LL<<(n))
using namespace std;

//  types
typedef pair<int, int> P;
typedef pair<ll, int> Pl;
typedef pair<ll, ll> Pll;
typedef pair<double, double> Pd;
typedef complex<double> cd;
 
// constants
const int inf = 1e9;
const ll linf = 1LL << 50;
const double EPS = 1e-10;
const int mod = 1e9 + 7;
const int dx[4] = {-1, 0, 1, 0};
const int dy[4] = {0, -1, 0, 1};

// solve
template <class T>bool chmax(T &a, const T &b){if(a < b){a = b; return 1;} return 0;}
template <class T>bool chmin(T &a, const T &b){if(a > b){a = b; return 1;} return 0;}
template <typename T> istream &operator>>(istream &is, vector<T> &vec){for(auto &v: vec)is >> v; return is;}
template <typename T> ostream &operator<<(ostream &os, const vector<T>& vec){for(int i = 0; i < vec.size(); i++){ os << vec[i]; if(i + 1 != vec.size())os << " ";} return os;}
template <typename T> ostream &operator<<(ostream &os, const set<T>& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;}
template <typename T> ostream &operator<<(ostream &os, const unordered_set<T>& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;}
template <typename T> ostream &operator<<(ostream &os, const multiset<T>& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;}
template <typename T> ostream &operator<<(ostream &os, const unordered_multiset<T>& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;}
template <typename T1, typename T2> ostream &operator<<(ostream &os, const pair<T1, T2> &p){os << p.first << " " << p.second; return os;}
template <typename T1, typename T2> ostream &operator<<(ostream &os, const map<T1, T2> &mp){for(auto itr = mp.begin(); itr != mp.end(); ++itr){ os << itr->first << ":" << itr->second; auto titr = itr; if(++titr != mp.end())os << " "; } return os;}
template <typename T1, typename T2> ostream &operator<<(ostream &os, const unordered_map<T1, T2> &mp){for(auto itr = mp.begin(); itr != mp.end(); ++itr){ os << itr->first << ":" << itr->second; auto titr = itr; if(++titr != mp.end())os << " "; } return os;}

template <typename T>
struct edge {int to; T cap; T cost; int rev;};

template <typename T>
struct Graph{
  int n;
  vector<vector<edge<T>>> vec;
  Graph(int n): n(n){
    vec.resize(n);
  }
  void adde(int at, int to, T cap, T cost){
    vec[at].push_back((edge<T>){to, cap, cost, (int)vec[to].size()});
    vec[to].push_back((edge<T>){at, 0, -cost, (int)vec[at].size() - 1});
  }
  T min_cost_flow(int s, int t, T f){
    T res = 0;
    vector<T> dis(n, 0);
    vector<int> prevv(n), preve(n);
    T inf = numeric_limits<T>::max();
    while(f > 0){
      fill(dis.begin(), dis.end(), inf);
      dis[s] = 0;
      bool update = true;
      while(update){
        update = false;
        for(int i = 0; i < n; i++){
          if(dis[i] == inf)continue;
          for(int j = 0; j < vec[i].size(); j++){
            auto e = vec[i][j];
            if(e.cap > 0 && dis[e.to] > dis[i] + e.cost){
              dis[e.to] = dis[i] + e.cost;
              prevv[e.to] = i;
              preve[e.to] = j;
              update = true;
            }
          }
        }
      }

      if(dis[t] == inf)return -1;
      T d = f;
      for(int i = t; i != s; i = prevv[i]){
        d = min(d, vec[prevv[i]][preve[i]].cap);
      }
      f -= d;
      res += d * dis[t];
      for(int i = t; i != s; i = prevv[i]){
        auto& e = vec[prevv[i]][preve[i]];
        e.cap -= d;
        vec[i][e.rev].cap += d;
      }
    }
    return res;
  }
};

using GraphI = Graph<int>;
using GraphL = Graph<long long>;

int main(int argc, char const* argv[])
{
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  int n, m, f;
  cin >> n >> m >> f;
  GraphI graph(n);
  rep(i, m){
    int u, v, c, d;
    cin >> u >> v >> c >> d;
    graph.adde(u, v, c, d);
  }
  cout << graph.min_cost_flow(0, n - 1, f) << endl;
  return 0;
}



Measured memory_bytes: 3288