// May this submission get accepted
#include <bits/stdc++.h>

// エイリアス
using  ll = long signed long;
using ull = long unsigned long;
using  ld = long double;
using namespace std;

// AtCoder/Codeforces 用 デバッグ検知
#ifdef ONLINE_JUDGE
constexpr bool DEBUG_MODE = false;
#else
constexpr bool DEBUG_MODE = true;
#endif

// エイリアス (補完・コンパイルが重くなる)
// #include <boost/multiprecision/cpp_int.hpp>
// using mll = boost::multiprecision::cpp_int;

// 汎用マクロ
#define ALL_OF(x) (x).begin(), (x).end()
#define REP(i,n) for (long long i=0, i##_len=(n); i<i##_len; i++)
#define RANGE(i,is,ie) for (long long i=(is), i##_end=(ie); i<=i##_end; i++)
#define DSRNG(i,is,ie) for (long long i=(is), i##_end=(ie); i>=i##_end; i--)
#define STEP(i, is, ie, step) for (long long i=(is), i##_end=(ie), i##_step = (step); i<=i##_end; i+=i##_step)
#define UNIQUE(v) do { sort((v).begin(), (v).end()); (v).erase(unique((v).begin(), (v).end()), (v).end()); } while (false)
#define FOREACH(i,q) for (auto &i : q)
template<class T> bool chmax(T &a, const T b) { if (a < b) {a = b; return true;} return false; }
template<class T> bool chmin(T &a, const T b) { if (a > b) {a = b; return true;} return false; }
constexpr int INF = numeric_limits<int>::max();
constexpr long long LINF = numeric_limits<long long>::max();
constexpr long double EPS = 1e-10L;
#define Yes(q) ((q) ? "Yes" : "No")
#define YES(q) ((q) ? "YES" : "NO")
#define Possible(q) ((q) ? "Possible" : "Impossible")
#define POSSIBLE(q) ((q) ? "POSSIBLE" : "IMPOSSIBLE")
#define IIF(q,t,f) ((q) ? (t) : (f))
#define DUMP(q) DUMP_FUNC(q, #q, __FILE__, __LINE__)
template <typename T> void DUMP_PROC(T x) { if (is_integral<T>() || is_floating_point<T>()) cerr << "\e[32m" << x << "\e[m"; else cerr << x; }
template<> void DUMP_PROC<char>(char x) { cerr << "\e[36m\'" << x << "\'\e[m"; }
template<> void DUMP_PROC<string>(string x) { cerr << "\e[33m\"" << x << "\"\e[m"; }
template <typename T, typename U> void DUMP_PROC(pair<T, U> x) { cerr << "{"; DUMP_PROC(x.first); cerr << ", "; DUMP_PROC(x.second); cerr << "}"; }
template <typename ...T, typename U, U... Seq> void DUMP_PROC(tuple<T...> &x, integer_sequence<U, Seq...>) { (void)(int[]){(cerr << ((const char*[]){"", ", "})[!!Seq] << (DUMP_PROC(get<Seq>(x)), ""), 0)...}; }
template <typename ...T> void DUMP_PROC(tuple<T...> x) {cerr << "{"; DUMP_PROC(x, index_sequence_for<T...>()); cerr << "}";}
template <typename T> void DUMP_PROC(vector<T> x) { cerr << "["; for (auto &xi : x) { DUMP_PROC(xi); cerr << (&xi != &*x.rbegin()?", ":""); } cerr << "]"; }
template <typename T> void DUMP_FUNC(T x, const char* name, const char* fn, int ln) { cerr << "\e[32m[DEBUG]\e[m " << name << ": "; DUMP_PROC(x); cerr << " @ " << fn << "(" << ln << ")" << endl; }

// gcc拡張マクロ
#define popcount __builtin_popcount
#define popcountll __builtin_popcountll

// 標準入出力
struct qin { // query input
    size_t sz;
    qin(size_t _sz = 1) : sz(_sz) {}
    template <typename T> operator T () const { T a; cin >> a; return a; }
    template <typename T> operator vector<T> () const { vector<T> a(sz); for (size_t i = 0; i < sz; i++) cin >> a[i]; return a; }
    template <typename T, typename U> operator pair<T, U> () const { T f; U s; cin >> f >> s; return pair<T, U>(f, s); }
};
qin in1; // input one
template <typename T> void say(const T x, const char* end = "\n") { cout << x << end; }
void say(const ld x, const char* end = "\n") { cout << setprecision(30) << x << end; }
template <typename T> void say(const vector<T> x, const char* sep = " ", const char* end = "\n") { REP(i, x.size()) { cout << x[i] << (i+1 == i_len ? end : sep); } }
template <typename T> void say(const vector<vector<T>> x, const char* sep = " ", const char* end = "\n") { REP(i, x.size()) { say(x[i], sep, end); } }

// モジュール
// [[LIBRARY]]
// [[/LIBRARY]]

// 最小費用流 ポテンシャル付き O(FElogV)
// CapacityとCostは符号付き整数型である必要がある（整数型でないと停止しない場合がある，符号付きでないと逆辺がバグる）
template <typename Capacity = long long, typename Cost = long long>
struct min_cost_flow {

    using edge = tuple<size_t, Capacity, Cost, size_t>; // {to, cap, cost, rev}
    
    size_t n;
    vector<vector<edge>> g;

    min_cost_flow(): n(0), g() {}
    min_cost_flow(size_t _n): n(_n), g(n) {}

    void add_arc(size_t from, size_t to, Capacity cap, Cost cost) {
        g[from].emplace_back(to  , cap,  cost, g[to].size());
        g[to  ].emplace_back(from,   0, -cost, g[from].size()-1);
    }

    // 流せない場合，numeric_limits<Cost>::max()が返る
    Cost min_cost(size_t s, size_t t, Capacity f) {
        Cost CINF = numeric_limits<Cost>::max();
        Cost FINF = numeric_limits<Capacity>::max();
        Cost result = 0;
        vector<Cost> h(n, 0); // ポテンシャル
        while (f > 0) {
            // Dijkstra法+ポテンシャルで最短路を見つける
            using qitem = pair<Cost, size_t>;
            priority_queue<qitem, vector<qitem>, greater<qitem>> q;
            vector<Cost> dist(n, CINF);
            vector<size_t> prevv(n), preve(n);
            dist[s] = 0;
            q.push(qitem(0, s));
            while (q.size()) {
                const auto du = q.top(); q.pop();
                Cost d; size_t u; tie(d, u) = du;
                REP(i, g[u].size()) {
                    size_t to, rev; Capacity cap; Cost cost;
                    tie(to, cap, cost, rev) = g[u][i];
                    if (cap > 0 && chmin(dist[to], dist[u] + cost + h[u] - h[to])) {
                        prevv[to] = u;
                        preve[to] = i;
                        q.push(qitem(dist[to], to));
                    }
                }
            }
            if (dist[t] == CINF) return CINF;
            REP(i, n) h[i] += dist[i];
            // 最短路に流す
            Capacity d = f;
            for (size_t i = t; i != s; i = prevv[i]) {
                auto &e = g[prevv[i]][preve[i]];
                chmin(d, get<1>(e));
            }
            f -= d;
            result += d * h[t];
            for (size_t i = t; i != s; i = prevv[i]) {
                auto &e = g[prevv[i]][preve[i]];
                auto &r = g[i][get<3>(e)];
                get<1>(e) -= d;
                get<1>(r) += d;
            }
        }
        return result;
    }

};

// 処理内容
int main() {
    
    ios::sync_with_stdio(false); // stdioを使うときはコメントアウトすること
    cin.tie(nullptr);            // インタラクティブ問題ではコメントアウトすること
    
    ll n, m, f; cin >> n >> m >> f;
    min_cost_flow<> mcf(n);
    REP(i, m) {
        ll u, v, c, d;
        cin >> u >> v >> c >> d;
        mcf.add_arc(u, v, c, d);
    }

    auto ans = mcf.min_cost(0, n-1, f);
    say(ans == numeric_limits<decltype(ans)>::max() ? -1 : ans);
    
}


Measured memory_bytes: 3284