#include<iostream>
#include<vector>
#include<map>
#include<algorithm>

bool less(std::pair<int, int> lhs, std::pair<int, int> rhs) {
  if(lhs.first == rhs.first) {
    return lhs.second < rhs.second;
  }
  return lhs.first < rhs.first;
}

std::pair<int, int> plus(std::pair<int, int> lhs, std::pair<int, int> rhs) {
  return std::make_pair(lhs.first + rhs.first, lhs.second + rhs.second);
}

static int const INF{100000000};

int main(int, char**) {
  int N, C, V;
  std::cin >> N >> C >> V;

  std::vector<int> ss(N), ts(N), ys(N),ms(N);
  for(int i{0}; i < N; ++i) {
    std::cin >> ss[i];
  }
  for(int i{0}; i < N; ++i) {
    std::cin >> ts[i];
  }
  for(int i{0}; i < N; ++i) {
    std::cin >> ys[i];
  }
  for(int i{0}; i < N; ++i) {
    std::cin >> ms[i];
  }

  std::vector<std::pair<int, int>> vs(N);
  for(int i{0}; i < N; ++i) {
    vs[i] = std::make_pair(ms[i], ys[i]);
  }

  std::vector<std::vector<std::pair<int, int>>> ns(N, std::vector<std::pair<int, int>>(1, std::make_pair(INF, INF)));
  ns[0] = std::vector<std::pair<int, int>>(1, std::make_pair(0, 0));

  for(int i{0}; i < V; ++i) {
    int const s = ss[i] - 1;
    int const t = ts[i] - 1;

    for(auto c: ns[s]) {
      auto new_cost = plus(c, vs[i]);
      ns[t].push_back(new_cost);
    }

    auto& n = ns[t];
    auto it = std::remove_if(begin(n), end(n), [C](auto x) { return x.second > C; });
    n.erase(it, end(n));
  }

  auto& n = ns[N - 1];
  std::sort(begin(n), end(n), less);
  if(begin(n) == end(n) || n[0].first == INF) {
    std::cout << -1 << std::endl;
  } else {
    std::cout << n[0].first << std::endl;
  }

  return 0;
}