#include <bits/stdc++.h>

using namespace std;
using ll = long long;

constexpr ll mod = 998244353;

template<ll mod>
struct Mint {
  using M=Mint; ll v;
  M& put(ll x) { v=(x<mod)?x:x-mod; return *this; }
  Mint(ll x=0) { put(x%mod+mod); }
  M operator+(M m) {return M().put(v+m.v);}
  M operator-(M m) {return M().put(v+mod-m.v);}
  M operator*(M m) {return M().put(v*m.v%mod);}
  M operator/(M m) {return M().put(v*m.inv().v%mod);}
// BEGIN IGNORE
  M operator+=(M m) { return put(v+m.v); }
  M operator-=(M m) { return put(v+mod-m.v); }
  M operator*=(M m) { return put(v*m.v%mod); }
  M operator/=(M m) { return put(v*m.inv().v%mod); }
// END IGNORE
  bool operator==(M m) { return v==m.v; }
  M pow(ll m) const {
    M x=v, res=1;
    while (m) {
      if (m&1) res=res*x;
      x=x*x; m>>=1;
    }
    return res;
  }
  M inv() { return pow(mod-2); }
};

using mint = Mint<mod>;


int main(){

  cin.tie(0);
  cin.sync_with_stdio(0);

  int n, m, x;
  cin >> n >> m >> x;
  vector<vector<pair<ll,ll>>> edges(n);
  for(int i = 0; i < m; ++i){
    int u, v, c, t;
    cin >> u >> v >> c >> t;
    --u, --v;
    edges[u].emplace_back(v, c + 1ll * t * x);
    edges[v].emplace_back(u, c + 1ll * t * x);
  }
  vector<ll> dp(n, 1e18);
  dp[0] = 0;
  priority_queue<pair<ll,int>, vector<pair<ll,int>>, greater<>> que;
  que.emplace(0, 0);
  while(!que.empty()){
    auto [d, pos] = que.top();
    que.pop();
    if(dp[pos] != d)continue;
    for(auto [to, cos] : edges[pos]){
      if(dp[to] > d + cos){
        dp[to] = d + cos;
        que.emplace(d + cos, to);
      }
    }
  }
  if(dp.back() == 1e18){
    cout << -1 << endl;
  }
  else{
    cout << (dp.back() + x - 1) / x << endl;
  }
}