#include <iostream>
#include <vector>
#include <tuple>

template <class T>
std::vector<T> vec(int len, T elem) { return std::vector<T>(len, elem); }

constexpr int INF = 1 << 30;

void solve() {
    int n, k;
    std::cin >> n >> k;

    std::vector<std::vector<std::tuple<int, int, int>>> ess(n);
    {
        int m;
        std::cin >> m;

        std::vector<int> us(m), vs(m), cs(m), ts(m);
        for (auto& u : us) std::cin >> u;
        for (auto& v : vs) std::cin >> v;
        for (auto& c : cs) std::cin >> c;
        for (auto& t : ts) std::cin >> t;

        for (int i = 0; i < m; ++i) {
            ess[--us[i]].emplace_back(--vs[i], cs[i], ts[i]);
        }
    }

    auto dp = vec(n, vec(k + 1, INF));
    std::fill(dp[0].begin(), dp[0].end(), 0);

    for (int u = 0; u < n; ++u) {
        for (auto [v, c, t] : ess[u]) {
            for (int x = 0; x + c <= k; ++x) {
                dp[v][x + c] = std::min(dp[v][x + c], dp[u][x] + t);
            }
        }
    }

    int ans = dp[n - 1][k];
    std::cout << (ans == INF ? -1 : ans) << "\n";
}

int main() {
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    solve();

    return 0;
}