#include <bits/stdc++.h>

using namespace std;

const int INF = 1<<30;

int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);

  int n, m, c;
  cin >> n >> c >> m;

  vector<int> s(m), t(m), y(m), w(m);
  for (int i = 0; i < m; i++) cin >> s[i];
  for (int i = 0; i < m; i++) cin >> t[i];
  for (int i = 0; i < m; i++) cin >> y[i];
  for (int i = 0; i < m; i++) cin >> w[i];  

  vector<vector<tuple<int, int, int> > >edges(n);
  for (int i = 0; i < m; i++) {
    edges[s[i]-1].emplace_back(t[i]-1, y[i], w[i]);
  }

  vector<vector<int> > dist(n, vector<int>(c+1, INF));
  priority_queue<tuple<int, int, int>, vector<tuple<int, int, int>>, greater<tuple<int, int, int>> > q;

  dist[0][c] = 0;
  q.emplace(0, 0, c);

  while (!q.empty()) {
    int cost, v, r;
    tie(cost, v, r) = q.top();
    q.pop();
    if (cost > dist[v][r])
      continue;

    for (auto &[u, money, weight]: edges[v]) {
      if (r >= money && cost + weight < dist[u][r - money]) {
        dist[u][r - money] = cost + weight;
        q.emplace(dist[u][r - money], u, r - money);
      }
    }
  }
  
  int ret = *min_element(dist[n-1].begin(), dist[n-1].end());
  if (ret == INF)
    ret = -1;
  cout << ret << endl;
  
  return 0;
}