#include<bits/stdc++.h>
#include<atcoder/all>
#include"testlib.h"
using namespace std;
using ll = long long;

const ll Nmin = 1, Nmax = 100'000;
const ll Kmin = 1, Kmax = 100'000;
const ll Cmin = 1, Cmax = 10'000'000'000LL;
const ll WPmin = 1, WPmax = 100'000;

int main(){
    registerValidation();
    ll n = inf.readLong(Nmin,Nmax);
    inf.readSpace();
    ll k = inf.readLong(Kmin,Kmax);
    inf.readSpace();
    ll c = inf.readLong(Cmin,Cmax);
    inf.readEoln();
    atcoder::dsu d(n);
    set<pair<ll,ll>> es;
    for (ll i = 0; i < k; i++){
        ll u = inf.readLong(1LL,n);
        inf.readSpace();
        ll v = inf.readLong(1LL,n);
        inf.readSpace();
        ll w = inf.readLong(WPmin,WPmax);
        inf.readSpace();
        ll p = inf.readLong(WPmin,WPmax);
        inf.readEoln();
        ensuref(u != v, "self loop");
        if (u > v) swap(u,v);
        es.insert(pair<ll,ll>(u,v));
        u--, v--;
        d.merge(u,v);
    }
    ensuref((ll)(es.size()) == k, "multiple edge");
    ensuref((ll)(d.size(0)) == n, "not connected");
    inf.readEof();
}