#include<atcoder/all>
using namespace atcoder;

#include <bits/stdc++.h>
template<class T> inline bool chmin(T&a, T b){if(a > b){a = b; return true;}else{return false;}}
template<class T> inline bool chmax(T&a, T b){if(a < b){a = b; return true;}else{return false;}}
#define ll long long
#define double long double
#define rep(i,n) for(int i=0;i<(n);i++)
#define REP(i,n) for(int i=1;i<=(n);i++)
#define mod (ll)(1e9+7)
#define inf (ll)(3e18+7)
#define eps (double)(1e-9)
#define pi (double) acos(-1)
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
using namespace std;
 
struct edge{
    ll to, cost;
};

vector<vector<edge>> G(200010);
vector<ll> d(200010, inf);


#define P pair<ll, int>
void dijkstra(int s) {
	priority_queue<P, vector<P>, greater<P>>que;
	d[s] = 0;
	que.push(P(0, s));
	while (!que.empty()) {
		P p = que.top(); que.pop();
		int v = p.second;
		if (d[v] < p.first)continue;
		rep(i, G[v].size()) {
			edge e = G[v][i];
			if (d[e.to] > d[v] + e.cost) {
				d[e.to] = d[v] + e.cost;
				que.push(P(d[e.to], e.to));
			}
		}
	}
}

int main() {
    ll n, m, x;
    cin >> n >> m >> x;

    rep(i, m){
        ll u, v, c, t;
        cin >> u >> v >> c >> t;
        u--; v--;

        G[u].push_back({v, t * x + c});
        G[v].push_back({u, t * x + c});
    }

    dijkstra(0);

    if(d[n-1] == inf)cout << -1 << endl;
    else cout << (d[n-1] + x - 1) / x << endl;
}