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

using namespace std;
typedef long long ll;
//typedef unsigned long long ll;

#define rep(i, n) for (int i = 0; i < (n); ++i)
//#define rep(i, n) for (ll i = 0; i < (n); ++i)
//#define sz(x) ll(x.size())
//typedef pair<ll, int> P;
typedef pair<ll, ll> P;
//const double INF = 1e10;
const ll INF = LONG_LONG_MAX / 100;
//const ll INF = (1ll << 31) - 1;
//const ll INF = 1e15;
const ll MINF = LONG_LONG_MIN;
//const int INF = INT_MAX / 10;
#define cmin(x, y) x = min(x, y)
#define cmax(x, y) x = max(x, y)
//typedef pair<int, int> P;
//typedef pair<double, double> P;

bool contain(set<P> &s, P a) { return s.find(a) != s.end(); }

//ifstream myfile("C:\\Users\\riku\\Downloads\\0_00.txt");
//ofstream outfile("log.txt");
//outfile << setw(6) << setfill('0') << prefecture << setw(6) << setfill('0') << rank << endl;
// std::cout << std::bitset<8>(9);
const int mod = 1000000007;
typedef priority_queue<long long, vector<long long>, greater<long long>> PQ_ASK;


void print_line(vector<string> &line) {
    if (line.size() == 0ll) {
        cout << endl;
        return;
    }
    for (ll i = 0; i < line.size(); i++) {
        cout << line[i];
        if (i == line.size() - 1) cout << endl;
        else cout << ' ';
    }
}

template<typename flow_t, typename cost_t>
struct PrimalDual {
    const cost_t INF;

    struct edge {
        int to;
        flow_t cap;
        cost_t cost;
        int rev;
        bool isrev;
    };
    vector<vector<edge> > graph;
    vector<cost_t> potential, min_cost;
    vector<int> prevv, preve;

    PrimalDual(int V) : graph(V), INF(numeric_limits<cost_t>::max()) {}

    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});
    }

    cost_t min_cost_flow(int s, int t, flow_t f) {
        int V = (int) graph.size();
        cost_t ret = 0;
        using Pi = pair<cost_t, int>;
        priority_queue<Pi, vector<Pi>, greater<Pi> > que;
        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;
    }

    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 v, e, f;
    cin >> v >> e >> f;

    PrimalDual<ll, ll> primalDual(v);
    rep(i, e) {
        ll ui, vi, capi, costi;
        cin >> ui >> vi >> capi >> costi;
        primalDual.add_edge(ui, vi, capi, costi);
    }

    cout << primalDual.min_cost_flow(0, v - 1, f) << endl;
}



Measured memory_bytes: 3280