#line 2 "cpplib/util/template.hpp"
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("avx2")
#include<bits/stdc++.h>
using namespace std;
struct __INIT__{__INIT__(){cin.tie(0);ios::sync_with_stdio(false);cout<<fixed<<setprecision(15);}}__INIT__;
typedef long long lint;
#define INF (1LL<<60)
#define IINF (1<<30)
#define EPS (1e-10)
#define endl ('\n')
typedef vector<lint> vec;
typedef vector<vector<lint>> mat;
typedef vector<vector<vector<lint>>> mat3;
typedef vector<string> svec;
typedef vector<vector<string>> smat;
template<typename T>using V=vector<T>;
template<typename T>using VV=V<V<T>>;
template<typename T>inline void output(T t){bool f=0;for(auto i:t){cout<<(f?" ":"")<<i;f=1;}cout<<endl;}
template<typename T>inline void output2(T t){for(auto i:t)output(i);}
template<typename T>inline void debug(T t){bool f=0;for(auto i:t){cerr<<(f?" ":"")<<i;f=1;}cerr<<endl;}
template<typename T>inline void debug2(T t){for(auto i:t)output(i);}
#define loop(n) for(long long _=0;_<(long long)(n);++_)
#define rep(i,...) for(auto i:range(__VA_ARGS__)) 
#define rrep(i,...) for(auto i:reversed(range(__VA_ARGS__)))
#define repi(i,a,b) for(lint i=lint(a);i<(lint)(b);++i)
#define rrepi(i,a,b) for(lint i=lint(b)-1;i>=lint(a);--i)
#define irep(i) for(lint i=0;;++i)
inline vector<long long> range(long long n){if(n<=0)return vector<long long>();vector<long long>v(n);iota(v.begin(),v.end(),0LL);return v;}
inline vector<long long> range(long long a,long long b){if(b<=a)return vector<long long>();vector<long long>v(b-a);iota(v.begin(),v.end(),a);return v;}
inline vector<long long> range(long long a,long long b,long long c){if((b-a+c-1)/c<=0)return vector<long long>();vector<long long>v((b-a+c-1)/c);for(int i=0;i<(int)v.size();++i)v[i]=i?v[i-1]+c:a;return v;}
template<typename T>inline T reversed(T v){reverse(v.begin(),v.end());return v;}
#define all(n) begin(n),end(n)
template<typename T,typename E>bool chmin(T& s,const E& t){bool res=s>t;s=min<T>(s,t);return res;}
template<typename T,typename E>bool chmax(T& s,const E& t){bool res=s<t;s=max<T>(s,t);return res;}
const vector<lint> dx={1,0,-1,0,1,1,-1,-1};
const vector<lint> dy={0,1,0,-1,1,-1,1,-1};
#define SUM(v) accumulate(all(v),0LL)
template<typename T,typename ...Args>auto make_vector(T x,int arg,Args ...args){if constexpr(sizeof...(args)==0)return vector<T>(arg,x);else return vector(arg,make_vector<T>(x,args...));}
#define extrep(v,...) for(auto v:__MAKE_MAT__({__VA_ARGS__}))
vector<vector<long long>> __MAKE_MAT__(vector<long long> v){if(v.empty())return vector<vector<long long>>(1,vector<long long>());long long n=v.back();v.pop_back();vector<vector<long long>> ret;vector<vector<long long>> tmp=__MAKE_MAT__(v);for(auto e:tmp)for(long long i=0;i<n;++i){ret.push_back(e);ret.back().push_back(i);}return ret;}
//#include "../graph_tree/graph_template.hpp"
template<typename T,typename E>ostream& operator<<(ostream& out,pair<T,E>v){out<<"("<<v.first<<","<<v.second<<")";return out;}
#line 1 "cpplib/dsu/union_find.hpp"
/**
 * @brief Union Find
 * @see https://ja.wikipedia.org/wiki/%E7%B4%A0%E9%9B%86%E5%90%88%E3%83%87%E3%83%BC%E3%82%BF%E6%A7%8B%E9%80%A0
 */

class UF{
    public:
    vector<int> data;
    int sz;
	public:
    UF(int sz):sz(sz){data.resize(sz,-1);}
    bool unite(int x,int y){
        x=root(x);y=root(y);
        if(x==y)return 0;
        if(data[x]>data[y])swap(x,y);
		data[x]+=data[y];
		data[y]=x;
		sz--;
        return 1;
    }
    inline int root(int x){return data[x]<0?x:data[x]=root(data[x]);}
    inline bool same(int x, int y){return root(x)==root(y);}
    inline int size(){return sz;}
	inline int size(int x){return -data[root(x)];}
};
#line 3 "cpplib/math/binary_search_double.hpp"
/**
 * @brief 二分探索(double)
 */

template<typename F>
long double bs(long double mn,long double mx,F func) {
    long double left = mn;
    long double right =mx;
    for(int i=0;i<100;i++){
        long double mid=(right+left)*0.5;
        if (!func(mid)) right = mid;
        else left = mid;
    }
    return left;
}
#line 4 "code.cpp"

int main(){
    lint n,m,k;
    cin>>n>>m>>k;
    vec a(m),b(m),c(m),d(m);
    rep(i,m){
        cin>>a[i]>>b[i]>>c[i]>>d[i];
        assert(1<=a[i]&&a[i]<=n);
        assert(1<=b[i]&&b[i]<=n);
        a[i]--;b[i]--;
    }
    auto g=[&](vector<long double> x){
        long double ans=0;
        rep(i,m){
            ans-=d[i]*x[i];
        }
        return ans;
    };
    auto f=[&](vector<long double> x){
        vector<tuple<long double,lint,lint>>v;
        long double ans=0;
        rep(i,m){
            v.emplace_back(c[i]+x[i],a[i],b[i]);
        }
        sort(all(v));
        UF uf(n);
        rep(i,m){
            if(uf.unite(get<1>(v[i]),get<2>(v[i]))){
                ans+=get<0>(v[i])*k;
            }
        }
        return ans;
    };
    auto p=[&](vector<long double> x){
        vector<tuple<long double,lint,lint,lint>>v;
        vector<lint>res(m,0);
        rep(i,m){
            v.emplace_back(c[i]+x[i],a[i],b[i],i);
        }
        sort(all(v));
        UF uf(n);
        rep(i,m){
            if(uf.unite(get<1>(v[i]),get<2>(v[i]))){
                res[get<3>(v[i])]=k;
            }
        }
        return res;
    };
    lint cnt=10000;
    lint pre=0,ans=0;
    {
        vector<long double> x(m,0);
        long double eta=1.+0.5/m;
        for(int i=0;i<cnt;++i){
            auto k=p(x);
            rep(i,m){
                x[i]=max(0.L,x[i]+(k[i]-d[i])/eta);
            }
            eta*=1.+0.5/m;
        }
        pre=(lint)round(f(x)+g(x));
    }
    {
        vector<long double> x(m,0);
        long double eta=1;
        for(int i=0;i<cnt;++i){
            auto k=p(x);
            rep(i,m){
                x[i]=max(0.L,x[i]+(k[i]-d[i])/eta);
            }
            eta*=1.+0.5/m;
        }
        ans=(lint)round(f(x)+g(x));
    }
    if(pre!=ans){
        cout<<-1<<endl;
    }else{
        cout<<ans<<endl;
    }
}