#include <bits/stdc++.h>
using namespace std;
#define rep(i, x, limit) for (long long i = (long long)x; i < (long long)limit; i++)
#define REP(i, x, limit) for (long long i = (long long)x; i <= (long long)limit; i++)
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define el '\n'
#define spa " "
#define Yes cout << "Yes" << el
#define No cout << "No" << el
#define YES cout << "YES" << el
#define NO cout << "NO" << el
#define eps (1e-10)
#define Equals(a,b) (fabs((a) - (b)) < eps )
#define debug(x) cerr << #x << " = " << x << el
using ll = long long;
using ull = unsigned long long;
using pii = pair<int,int>;
using pll = pair<ll,ll>;
using vi = vector<int>;
using vl = vector<ll>;
using vvl = vector<vector<ll>>;
using vs = vector<string>;
using vb = vector<bool>;
const double pi = 3.141592653589793238;
const int inf = 1073741823;
const ll infl = 1LL << 60;
const string ABC = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
const string abc = "abcdefghijklmnopqrstuvwxyz";
const ll MOD = 998244353;
#include<atcoder/all>
using namespace atcoder;
using mint = modint998244353;
using vm = vector<mint>;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  ll n,m,x;cin>>n>>m>>x;
  using T=tuple<ll,ll,ll>;
  vector<vector<T>> G(n);
  rep(i,0,m){
    ll u,v,c,t;cin>>u>>v>>c>>t;
    u--;v--;
    G[u].emplace_back(v,c,t);
    G[v].emplace_back(u,c,t);
  }
  vector<pll> dist(n,{infl,infl});
  priority_queue<T,vector<T>,greater<T>> pq;
  pq.emplace(0,0,0);
  while(!pq.empty()){
    auto [time,money,v]=pq.top();pq.pop();
    if(dist[v]<=(pll{time,money}))continue;
    dist[v]={time,money};
    for(auto [to,cost,tt]:G[v]){
      ll nt=time+tt+(-money-cost>=0?0:(money+cost-1)/x+1);
      ll nm=money+cost-x*(-money-cost>=0?0:(money+cost-1)/x+1);
      if(dist[to]>(pll{nt,nm})){
        pq.emplace(nt,nm,to);
      }
    }
  }
  auto [ttt,mmm]=dist[n-1];
  if(ttt==infl)ttt=-1;
  cout<<ttt<<el;
}