#pragma GCC optimize ("O3")
#pragma GCC target ("avx")
#include "bits/stdc++.h" // define macro "/D__MAI"

using namespace std;
typedef long long int ll;

#define xprintf(fmt,...) fprintf(stderr,fmt,__VA_ARGS__)
#define debugv(v) {printf("L%d %s > ",__LINE__,#v);for(auto e:v){cout<<e<<" ";}cout<<endl;}
#define debuga(m,w) {printf("L%d %s > ",__LINE__,#m);for(int x=0;x<(w);x++){cout<<(m)[x]<<" ";}cout<<endl;}
#define debugaa(m,h,w) {printf("L%d %s >\n",__LINE__,#m);for(int y=0;y<(h);y++){for(int x=0;x<(w);x++){cout<<(m)[y][x]<<" ";}cout<<endl;}}
#define ALL(v) (v).begin(),(v).end()
#define repeat(cnt,l) for(auto cnt=0ll;(cnt)<(l);++(cnt))
#define iterate(cnt,b,e) for(auto cnt=(b);(cnt)!=(e);++(cnt))
#define MD 1000000007ll
#define PI 3.1415926535897932384626433832795
#define EPS 1e-12
template<typename T1, typename T2> ostream& operator <<(ostream &o, const pair<T1, T2> p) { o << "(" << p.first << ":" << p.second << ")"; return o; }
template<typename iterator> inline size_t argmin(iterator begin, iterator end) { return distance(begin, min_element(begin, end)); }
template<typename iterator> inline size_t argmax(iterator begin, iterator end) { return distance(begin, max_element(begin, end)); }
template<typename T> T& maxset(T& to, const T& val) { return to = max(to, val); }
template<typename T> T& minset(T& to, const T& val) { return to = min(to, val); }
void bye(string s, int code = 0) { cout << s << endl; exit(0); }
mt19937_64 randdev(8901016);
inline ll rand_range(ll l, ll h) {
    return uniform_int_distribution<ll>(l, h)(randdev);
}

#ifdef __MAI
#define getchar_unlocked getchar
#define putchar_unlocked putchar
#endif
#ifdef __VSCC
#define getchar_unlocked _getchar_nolock
#define putchar_unlocked _putchar_nolock
#endif
namespace {
#define isvisiblechar(c) (0x21<=(c)&&(c)<=0x7E)
    class MaiScanner {
    public:
        template<typename T> void input_integer(T& var) {
            var = 0;
            T sign = 1;
            int cc = getchar_unlocked();
            for (; cc<'0' || '9'<cc; cc = getchar_unlocked())
                if (cc == '-') sign = -1;
            for (; '0' <= cc&&cc <= '9'; cc = getchar_unlocked())
                var = (var << 3) + (var << 1) + cc - '0';
            var = var*sign;
        }
        inline int c() { return getchar_unlocked(); }
        inline MaiScanner& operator>>(int& var) {
            input_integer<int>(var);
            return *this;
        }
        inline MaiScanner& operator>>(long long& var) {
            input_integer<long long>(var);
            return *this;
        }
        inline MaiScanner& operator>>(string& var) {
            int cc = getchar_unlocked();
            for (; !isvisiblechar(cc); cc = getchar_unlocked());
            for (; isvisiblechar(cc); cc = getchar_unlocked())
                var.push_back(cc);
            return *this;
        }
        template<typename IT> void in(IT begin, IT end) {
            for (auto it = begin; it != end; ++it) *this >> *it;
        }
    };
}
MaiScanner scanner;


class Flow {
public:
    typedef int cap_t;
    size_t n;
    struct Arrow {
        int from, to;
        cap_t left;
        cap_t cap;

        Arrow(int from = 0, int to = 0, cap_t w = 1) :from(from), to(to), left(w), cap(w) {}
        bool operator<(const Arrow& a) const { return (left != a.left) ? left < a.left : (left<a.left) | (cap<a.cap) | (from<a.from) | (to<a.to); }
        bool operator==(const Arrow& a) const { return (from == a.from) && (to == a.to) && (left == a.left) && (cap == a.cap); }
    };
    vector<vector<int>> vertex_to;
    vector<vector<int>> vertex_from;
    vector<Arrow> arrows;

    Flow(int n) :n(n), vertex_to(n), vertex_from(n) { }

    void connect(int from, int to, cap_t left) {
        vertex_to[from].push_back(arrows.size()); // toto
        vertex_from[to].push_back(arrows.size()); // fromfrom
        arrows.emplace_back(from, to, left);
    }
};


Flow::cap_t minconstflow(Flow& graph, const vector<Flow::cap_t>& cost, int i_source, int i_sink, Flow::cap_t flow, Flow::cap_t inf) {

    Flow::cap_t total_cost = 0;
    vector<Flow::cap_t> ofs(graph.n); // potential
    vector<Flow::cap_t> dist(graph.n);
    vector<int> prev(graph.n);

    // static function<Flow::cap_t(int, Flow::cap_t)> _dfs = [&](int idx, Flow::cap_t f) {
    //     if (idx == i_source) return f;
    //     for (int ei : graph.vertex_from[idx]) {
    //         auto& edge = graph.arrows[ei];
    //         if (dist[edge.to] == dist[edge.from] + cost[ei] + ofs[edge.from] - ofs[edge.to]) {
    //             f = _dfs(edge.from, min(f, edge.left));
    //             if (f > 0) {
    //                 edge.left -= f;
    //                 return f;
    //             }
    //         }
    //     }
    //     for (int ei : graph.vertex_to[idx]) {
    //         auto& edge = graph.arrows[ei];
    //         if (dist[edge.from] == dist[edge.to] - cost[ei] + ofs[edge.to] - ofs[edge.from]) {
    //             f = _dfs(edge.to, min(f, edge.cap - edge.left));
    //             if (f > 0) {
    //                 edge.left += f;
    //                 return f;
    //             }
    //         }
    //     }
    //     return 0;
    // };

    while (flow > 0) {
        fill(dist.begin(), dist.end(), inf);
        fill(prev.begin(), prev.end(), -1);
        priority_queue<pair<Flow::cap_t, int>> pq;
        pq.emplace(0, i_source);
        dist[i_source] = 0;
        while (!pq.empty()) {
            auto p = pq.top(); pq.pop();
            int idx = p.second;
            if (dist[idx] < -p.first) continue;
            for (int ei : graph.vertex_to[idx]) {
                auto edge = graph.arrows[ei];
                if (0 < edge.left && dist[idx] + cost[ei] + ofs[idx] - ofs[edge.to] < dist[edge.to]) {
                    dist[edge.to] = dist[idx] + cost[ei] + ofs[idx] - ofs[edge.to];
                    prev[edge.to] = ei;
                    pq.emplace(-dist[edge.to], edge.to);
                }
            }
            for (int ei : graph.vertex_from[idx]) {
                auto edge = graph.arrows[ei];
                if (0 < edge.cap - edge.left && dist[idx] - cost[ei] + ofs[idx] - ofs[edge.from] < dist[edge.from]) {
                    dist[edge.from] = dist[idx] - cost[ei] + ofs[idx] - ofs[edge.from];
                    prev[edge.from] = ei;
                    pq.emplace(-dist[edge.from], edge.from);
                }
            }
        }
        if (dist[i_sink] == inf) return -1;
        for (int i = 0; i < graph.n; ++i)
            ofs[i] += dist[i];
        // Flow::cap_t z = _dfs(i_sink, flow);

        Flow::cap_t z = flow;
        for (int p = i_sink; p != i_source; ) {
            auto& edge = graph.arrows[prev[p]];
            if (edge.to == p)
                minset(z, edge.left),
                p = edge.from;
            else
                minset(z, edge.cap - edge.left),
                p = edge.to;
        }
        for (int p = i_sink; p != i_source; ) {
            auto& edge = graph.arrows[prev[p]];
            if (edge.to == p)
                edge.left -= z,
                total_cost += z*cost[prev[p]],
                p = edge.from;
            else
                edge.left += z,
                total_cost -= z*cost[prev[p]],
                p = edge.to;
        }
        flow -= z;
        // total_cost += z * ofs[i_sink];
    }

    return total_cost;
}


ll m, n, kei;

int main() {
    ll f;
    scanner >> n >> m >> f;

    Flow graph(n);

    vector<int> cost(m);

    repeat(i, m) {
        int u, v, c, d;
        scanner >> u >> v >> c >> d;
        graph.connect(u, v, c);
        cost[i] = d;
    }

    auto ans = minconstflow(graph, cost, 0, n - 1, f, (ll)1e8);
    
    // for (auto e : graph.arrows){
    //     printf("%d->%d %d/%d\n", e.from, e.to, e.cap-e.left, e.cap);
    // }
    
    cout << ans << endl;

    return 0;
}

Measured memory_bytes: 3176