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

#define rep(i,n) for(int i=0;i<(n);++i)
#define loop for(;;)
#define trace(var) cerr<<">>> "<<#var<<" = "<<var<<endl;
#define all(v) begin(v),end(v)
#define pb push_back
#define inf (1e9)
#define eps (1e-9)
using Integer = long long;
using Real = long double;
const Real PI = acosl(-1);
using P = pair<int, int>;

template<class S, class T> inline
ostream& operator<<(ostream&os, pair<S,T> p) {
  return os << '(' << p.first << ", " << p.second << ')';
}

template<class S, class T> inline
ostream& operator<<(ostream&os, tuple<S,T> t) {
  return os << '('
    << get<0>(t) << ", "
    << get<1>(t) << ')';
}

template<class S, class T, class U> inline
ostream& operator<<(ostream&os, tuple<S,T,U> t) {
  return os << '('
    << get<0>(t) << ", "
    << get<1>(t) << ", "
    << get<2>(t) << ')';
}

template<class T> inline
ostream& operator<<(ostream&os, set<T> v) {
  os << "(set";
  for (T item: v) os << ' ' << item;
  os << ")";
  return os;
}

template<class T> inline
ostream& operator<<(ostream&os, vector<T> v) {
  if (v.size() == 0) { return os << "(empty)"; }
  os << v[0];
  for (int i=1, len=v.size(); i<len; ++i) os << ' ' << v[i];
  return os;
}

template<class T> inline
istream& operator>>(istream&is, vector<T>&v) {
  rep (i, v.size()) is >> v[i];
  return is;
}

//           ^   >  v   <
int dx[] = { -1, 0, 1,  0 };
int dy[] = {  0, 1, 0, -1 };

using vi = vector<int>;
using vvi = vector<vi>;
using vd = vector<double>;
using vvd = vector<vd>;
using vb = vector<bool>;

int main() {

  int n, c, v; cin >> n >> c >> v;
  vi ss(v), ts(v), ys(v), ms(v);
  cin >> ss >> ts >> ys >> ms;

  rep (i, v) {
    ss[i]--;
    ts[i]--;
  }

  vvi rev(n);
  rep (i, v) {
    rev[ss[i]].push_back(i);
  }

  stack<tuple<int, int, int>> s;
  s.push(make_tuple(0, c, 0)); // (node, money, time)

  int ans = -1;
  while (not s.empty()) {
    int u, c, t;
    tie(u, c, t) = s.top(); s.pop();
    if (c<0) continue;
    if (u == n-1) {
      if (ans == -1 or ans > t) ans = t;
    }
    for (int i: rev[u]) {
      int v = ts[i];
      int d = ys[i];
      int dt = ms[i];
      if (c-d < 0) continue;
      s.push(make_tuple(v, c-d, t+dt));
    }
  }

  cout << ans << endl;

  return 0;
}