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

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n, m, u, v;
    ll x, c, t;
    cin >> n >> m >> x;
    vector<vector<pair<int,ll>>> g(n);
    for(int i = 0; i < m; i++){
        cin >> u >> v >> c >> t;
        u--, v--;
        g[u].emplace_back(v, c + t * x);
        g[v].emplace_back(u, c + t * x);
    }
    vector<ll> dp(n, 1ll << 62);
    priority_queue<pair<ll,int>, vector<pair<ll,int>>, greater<pair<ll,int>>> pq;
    pq.emplace(0, 0);
    dp[0] = 0;
    while(!pq.empty()){
        tie(t, v) = pq.top();
        pq.pop();
        if(t > dp[v]) continue;
        for(auto [u, w] : g[v]){
            if(t + w >= dp[u]) continue;
            dp[u] = t + w;
            pq.emplace(dp[u], u);
        }
    }
    cout << (dp.back() >> 62 ? -x : dp.back() + x - 1) / x << '\n';
}