#include<bits/stdc++.h>
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define rrep(i,n) for (int i = (n)-1; i >= 0; i--)
#define rep2(i,s,n) for (int i = (s); i < (n); ++i)
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
#define pb push_back
#define eb emplace_back
#define vi vector<int>
#define vvi vector<vector<int>>
#define vl vector<ll>
#define vvl vector<vector<ll>>
#define vs vector<string>
#define vc vector<char>
#define vb vector<bool>
#define vp vector<P>
using namespace std;
using ll = long long;
using P = pair<int,int>;
using LP = pair<ll,ll>;
template<class T> istream& operator>>(istream& is,vector<T>& v) { for(T& t:v){is>>t;} return is; }
template<class T> ostream& operator<<(ostream& os,const vector<T>& v) { for(T t:v){os<<t<<" ";} os<<"\n"; return os; }
void Yes(bool b) { cout << (b ? "Yes" : "No") << endl; }
void YES(bool b) { cout << (b ? "YES" : "NO") << endl; }
template<class T> inline bool chmin(T& a,T b) {if(a > b){a = b; return true;} return false;}
template<class T> inline bool chmax(T& a,T b) {if(a < b){a = b; return true;} return false;}
const int inf = 1001001001;
const ll linf = 1001001001001001001;

template<typename T>
class Mincostflow {
    using TP = pair<T,int>;
    struct edge {
        int to,cap,rev;
        T cost;
        edge(int to,int cap,T cost,int rev):to(to),cap(cap),cost(cost),rev(rev) {}
    };
    T tinf;
    int n;
    vector<vector<edge>> G;
    vector<T> pot,dist;
    vi prevv,preve;
    // potential
    void tinf_init(int x) { tinf = inf; }
    void tinf_init(ll x) { tinf = linf; }

public:
    explicit Mincostflow(int n):n(n),G(n),pot(n),dist(n),prevv(n),preve(n) {
        T x = 0; tinf_init(x);
    }
    void add_edge(int from,int to,T cap,int cost) {
        G[from].eb(to,cap,cost,G[to].size());
        G[to].eb(from,0,-cost,G[from].size()-1);
    }
    // return -1 if impossible
    T min_cost_flow(int s,int t,int f) {
        T res = 0;
        pot.assign(n,0);
        while(f > 0) {
            // use dijkstra to update pot
            priority_queue<TP,vector<TP>,greater<TP>> q;
            dist.assign(n,tinf);
            dist[s] = 0;
            q.emplace(0,s);
            while(!q.empty()) {
                T np = q.top().first;
                int v = q.top().second;
                q.pop();
                if(dist[v] < np) continue;
                rep(i,G[v].size()) {
                    edge &e = G[v][i];
                    if(e.cap > 0 && dist[e.to] > dist[v]+e.cost+pot[v]-pot[e.to]) {
                        dist[e.to] = dist[v]+e.cost+pot[v]-pot[e.to];
                        prevv[e.to] = v;
                        preve[e.to] = i;
                        q.emplace(dist[e.to],e.to);
                    }
                }
            }
            if(dist[t] == tinf) return -1;
            rep(i,n) pot[i] += dist[i];

            int d = f;
            for(int v = t; v != s; v = prevv[v]) {
                chmin(d,G[prevv[v]][preve[v]].cap);
            }
            f -= d;
            res += d*pot[t];
            for(int v = t; v != s; v = prevv[v]) {
                edge &e = G[prevv[v]][preve[v]];
                e.cap -= d;
                G[v][e.rev].cap += d;
            }
        }
        return res;
    };
};

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr); cout.tie(nullptr);
    int V,e,f;
    cin >> V >> e >> f;
    Mincostflow<int> fl(V);
    rep(_,e) {
        int u,v,c,d;
        cin >> u >> v >> c >> d;
        fl.add_edge(u,v,c,d);
    }
    cout << fl.min_cost_flow(0,V-1,f) << endl;
}



Measured memory_bytes: 3220