#include <bits/stdc++.h>
#define ll long long
#define MOD 1000000007
#define EPS 1e-10
#define rep(i,n) for(int i=0;i<(int)(n);++i)
#define rrep(i,n) for(int i=(int)(n)-1;i>=0;--i)
#define srep(i,s,t) for(int i=(int)(s);i<(int)(t);++i)
#define each(a,b) for(auto (a): (b))
#define all(v) (v).begin(),(v).end()
#define len(v) (int)(v).size()
#define zip(v) sort(all(v)),v.erase(unique(all(v)),v.end())
#define cmx(x,y) x=max(x,y)
#define cmn(x,y) x=min(x,y)
#define fi first
#define se second
#define pb push_back
#define show(x) cout<<#x<<" = "<<(x)<<endl
#define spair(p) cout<<#p<<": "<<p.fi<<" "<<p.se<<endl
#define svec(v) cout<<#v<<":";rep(kbrni,v.size())cout<<" "<<v[kbrni];cout<<endl
#define sset(s) cout<<#s<<":";each(kbrni,s)cout<<" "<<kbrni;cout<<endl
#define smap(m) cout<<#m<<":";each(kbrni,m)cout<<" {"<<kbrni.first<<":"<<kbrni.second<<"}";cout<<endl

using namespace std;

typedef pair<int,int> P;
typedef pair<ll,ll> pll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<double> vd;
typedef vector<P> vp;
typedef vector<string> vs;

template<typename CapType, typename CostType> class MinCostFlow {
public:
    using Cat = CapType;
    using Cot = CostType;
    using pti = pair<Cot, int>;
    struct edge {
        int to; Cat cap; Cot cost; int rev;
    };
    const int V;
    const Cot inf;
    vector<vector<edge> > G;
    vector<Cot> h, dist;
    vector<int> prevv, preve;
    MinCostFlow(int node_size) : V(node_size), inf(numeric_limits<Cot>::max()),
        G(V), h(V, 0), dist(V), prevv(V), preve(V){}
    void add_edge(int from, int to, Cat cap, Cot cost){
        G[from].push_back((edge){to, cap, cost, (int)G[to].size()});
        G[to].push_back((edge){from, 0, -cost, (int)G[from].size() - 1});
    }
    Cot solve(int s, int t, Cat f){
        Cot res = 0;
        while(f > 0){
            priority_queue<pti,vector<pti>,greater<pti> > que;
            fill(dist.begin(), dist.end(), inf);
            dist[s] = 0;
            que.push(pti(0, s));
            while(!que.empty()){
                pti p = que.top();
                que.pop();
                int v = p.second;
                if(dist[v] < p.first) continue;
                for(int i = 0; i < (int)G[v].size(); i++){
                    edge& e = G[v][i];
                    if(e.cap > 0 && dist[e.to] > dist[v] + e.cost + h[v] - h[e.to]){
                        dist[e.to] = dist[v] + e.cost + h[v] - h[e.to];
                        prevv[e.to] = v, preve[e.to] = i;
                        que.push(pti(dist[e.to], e.to));
                    }
                }
            }
            if(dist[t] == inf) return -1;
            for(int i = 0; i < V; i++){
                if(dist[i] != inf) h[i] += dist[i];
            }
            int d = f;
            for(int v = t; v != s; v = prevv[v]){
                d = min(d, G[prevv[v]][preve[v]].cap);
            }
            f -= d;
            res += d * h[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()
{
    int n,e,f;
    cin >> n >> e >> f;
    MinCostFlow<int, int> mc(n);
    rep(i,e){
        int u,v,c,d;
        cin >> u >> v >> c >> d;
        mc.add_edge(u,v,c,d);
    }
    cout << mc.solve(0,n-1,f) << "\n";
    return 0;
}



Measured memory_bytes: 3224