#include<bits/stdc++.h>
using namespace std;
#define ALL(x) x.begin(),x.end()
#define rep(i,n) for(int i=0;i<n;i++)
#define debug(v) cout<<#v<<":";for(auto x:v){cout<<x<<' ';}cout<<endl; 
//#define INF 1000000000
#define mod 1000000007
using ll=long long;
const ll LINF = 1001002003004005006ll;
int dx[]={1,0,-1,0};
int dy[]={0,1,0,-1};
ll gcd(ll a,ll b){return b?gcd(b,a%b):a;}
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }

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

    struct edge{
        int to;
        flow_t cap;
        cost_t cost;
        int rev;//この辺の逆辺がg[from]の何番目にあるか
        bool isrev;
    };

    vector<vector<edge>> graph;
    vector<cost_t> potential,min_cost;
    vector<int> prevv,preve;//点，辺

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

    void add_edge(int from,int to,flow_t cap,cost_t cost){
        graph[from].push_back((edge){to,cap,cost,(int)graph[to].size(),false});
        graph[to].push_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,TINF);
            que.emplace(0,s);
            min_cost[s]=0;
            //dijkstraパート
            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 and 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]==TINF) return -1;
            //dijkstraの結果に応じてpotentialを上げ下げ
            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];//天才じゃん
            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;
            }
        }
    }
};

signed main(){
    cin.tie(0);
    ios::sync_with_stdio(0);

    int n,m,f;
    cin>>n>>m>>f;
    int s=0,t=n-1;
    PrimalDual<int,int> flow(n);
    rep(i,m){
        int u,v,c,d;cin>>u>>v>>c>>d;
        flow.add_edge(u,v,c,d);
    }

    cout<<flow.min_cost_flow(s,t,f)<<endl;
    //flow.output();
    return 0;
}



Measured memory_bytes: 3264