#include<bits/stdc++.h>
#define overload(a,b,c,d,...) d
#define rep1(a) for(ll _=0;_<(ll)a;++_)
#define rep2(i,a) for(ll i=0;i<(ll)a;++i)
#define rep3(i,a,b) for(ll i=(ll)a;i<(ll)b;++i)
#define rep(...) overload(__VA_ARGS__,rep3,rep2,rep1)(__VA_ARGS__)
#define rrep1(i,a) for(ll i=(ll)a-1;i>=0;--i)
#define rrep2(i,a,b) for(ll i=(ll)b-1;i>=(ll)a;--i)
#define rrep(...) overload(__VA_ARGS__,rrep2,rrep1)(__VA_ARGS__)
#define eb emplace_back
#define pb push_back
#define all(v) (v).begin(),(v).end()
#define rall(v) (v).rbegin(),(v).rend()
#define lb(v,x) (lower_bound(all(v),x)-(v).begin())
#define ub(v,x) (upper_bound(all(v),x)-(v).begin())
using namespace std;
using ll=long long;
using vl=vector<ll>;
using ld=long double;
using i128=__int128_t;
template<typename T,typename U>inline static constexpr bool chmin(T&a,const U&b){return (a>b?a=b,true:false);}
template<typename T,typename U>inline static constexpr bool chmax(T&a,const U&b){return (a<b?a=b,true:false);}
static constexpr ll inf=numeric_limits<ll>::max()/2;
struct IOSetup{IOSetup(){ios::sync_with_stdio(false);cin.tie(nullptr);}};
static constexpr ll mod=998244353;
int main(){
    ll n,m,x;cin>>n>>m>>x;
    vector<vector<array<ll,3>>>g(n);
    rep(i,m){
        ll u,v,c,t;cin>>u>>v>>c>>t;
        u--,v--;
        g[u].pb({v,c,t});
        g[v].pb({u,c,t});
    }
    vector<pair<ll,ll>>dist(n,{inf,inf});
    dist[0]={0,0};
    priority_queue<pair<pair<ll,ll>,ll>,vector<pair<pair<ll,ll>,ll>>,greater<>>pq;
    pq.push({dist[0],0});
    while(!pq.empty()){
        auto [d,v]=pq.top();pq.pop();
        if(dist[v]<d)continue;
        for(auto [u,c,t]:g[v]){
            pair<ll,ll>nxt={dist[v].first+t,dist[v].second+c};
            nxt.first+=nxt.second/x;
            nxt.second%=x;
            if(chmin(dist[u],nxt))pq.push({dist[u],u});
        }
    }
    ll ans=dist[n-1].first+(dist[n-1].second==0?0:1);
    if(ans>=inf){
        cout<<-1<<endl;
    }
    else cout<<ans<<endl;
}