#include<bits/stdc++.h>
using namespace std;

//* ATCODER
#include<atcoder/all>
using namespace atcoder;
typedef modint998244353 mint;
//*/

/* BOOST MULTIPRECISION
#include<boost/multiprecision/cpp_int.hpp>
using namespace boost::multiprecision;
//*/

typedef long long ll;

#define rep(i, s, n) for (int i = (int)(s); i < (int)(n); i++)
#define rrep(i, s, n) for (int i = (int)(n)-1; i >= (int)(s); i--)

template <typename T> bool chmin(T &a, const T &b) {
	if (a <= b) return false;
	a = b;
	return true;
}

template <typename T> bool chmax(T &a, const T &b) {
	if (a >= b) return false;
	a = b;
	return true;
}

template <typename T> T max(vector<T> &a){
	assert(!a.empty());
	T ret = a[0];
	for (int i=0; i<(int)a.size(); i++) chmax(ret, a[i]);
	return ret;
}

template <typename T> T min(vector<T> &a){
	assert(!a.empty());
	T ret = a[0];
	for (int i=0; i<(int)a.size(); i++) chmin(ret, a[i]);
	return ret;
}

template <typename T> T sum(vector<T> &a){
	T ret = 0;
	for (int i=0; i<(int)a.size(); i++) ret += a[i];
	return ret;
}

int main(){
	int n, m;
	ll x; cin >> n >> m >> x;
	vector ikeru(n, vector<pair<int,ll>>(0));
	rep(i,0,m){
		int u, v; cin >> u >> v;
		u--; v--;
		ll c; cin >> c;
		ll t; cin >> t;
		ikeru[u].push_back(pair(v, c + t * x));
		ikeru[v].push_back(pair(u, c + t * x));
	}
	priority_queue<pair<ll,int>> pq;
	vector<ll> d(n, 4e18);
	d[0] = 0;
	pq.push(pair(0,0));
	while(!pq.empty()){
		auto[tmp,i]=pq.top();
		pq.pop();
		tmp=-tmp;
		if (tmp > d[i]) continue;
		for (auto[j,c]:ikeru[i]){
			if(chmin(d[j],c+d[i])){
				pq.push(pair(-d[j],j));
			}
		}
	}
	if (d[n-1]>1e18){
		cout <<-1 << '\n';
	}else{
		cout << (d[n-1]+x-1)/x << '\n';
	}
}