#include <fstream>
#include <vector>
#include <queue>
#define inf 200000000
using namespace std;
ifstream f("fmcm.in");
ofstream g("fmcm.out");

int N, M, x, y, z, c, cap[352][352], flow[352][352], D[352], ante[352];
vector <int> G[352];
queue <int> Q;
bool used[352], inQ[352];

bool bellman(int sursa)
{
    for (int i=1; i<=N; ++i)
        D[i]=ante[i]=inf, used[i]=0;
    Q.push(sursa); D[sursa]=0; used[sursa]=inQ[sursa]=1;
    while (Q.size())
    {
        int nod=Q.front(); inQ[nod]=0; ++used[nod];
        if (used[nod]==N) return 0;
        vector <int>::iterator it=G[nod].begin();
        for (; it!=G[nod].end(); ++it)
            if (D[nod]+cost[nod][*it]<D[*it] && cap[nod][*it]>flow[nod][*it])
            {
                D[*it]=D[nod]+cost[nod][*it];

                if (!inQ[*it]) inQ[*it]=1, Q.push(*it);
            }
    }
}

int main()
{
    f>>N>>M;
    for (int i=1; i<=M; ++i)
    {
        f>>x>>y>>z>>c; cap[x][y]=z; cost[x][y]=c; cost[y][x]=-c;
        G[x].push_back(y); G[y].push_back(x);
    }
    return 0;
}