#include <bits/stdc++.h>
#define rep(i, n) for(int i = 0; i < (int)(n); i++)
#define rep1(i, n) for(int i = 1; i <=(int)(n); i++)
#define all(obj) (obj).begin(), (obj).end()
typedef long long int ll;
using namespace std;

map<pair<int,int>, ll> mpc,mpt;
ll ans = -1;
int n,m;
ll x;

void dfs(int start,int goal,
    vector<vector<int>>& graph,
    vector<bool>&passed, 
    ll cost, ll time){

    if( start == goal){
        ll atime = cost / x;
        if( cost % x != 0) atime++;

        if( ans == -1){
            ans = atime+time;
        }else{
            ans = min(ans,atime+time);
        }
        return ;
    }

    passed[start] = true;
    for( auto nx: graph[start]){
        if( passed[nx] == false){
            dfs(nx,goal,graph,passed,
                cost+mpc[{start,nx}],
                time+mpt[{start,nx}]);
        }  
    }
    passed[start] = false;

}

int main() {
    cin >> n >> m >> x;
    vector<vector<int>> graph(n);
    rep(i,m){
        int u,v;
        ll c,t;
        cin >> u >> v >> c >> t;
        v--;
        u--;
        mpt[{u,v}] = t;
        mpc[{u,v}] = c;
        mpt[{v,u}] = t;
        mpc[{v,u}] = c;
        graph[u].push_back(v);
        graph[v].push_back(u);
    }

    vector<bool> passed(n,false);
    ans = -1;
    dfs(0,n-1,graph,passed,0,0);

    cout << ans << endl;
}