#include <iostream>
#include <vector>

int N;
int C;
int V;
std::vector<int> S, T, Y, M;

int compare(int t1, int t2) {
    if (t1 == -1) {
        return t2;
    } else if (t2 == -1) {
        return t1;
    } else if (t1 < t2) {
        return t1;
    } else {
        return t2;
    }
}

int solve(int town, int money, int elapsed) {
    int new_elapsed = -1;
    if (money < 0) {
        return -1;
    }
    if (town == 1) {
        return elapsed;
    }
    for (int i = 0; i < V; i++) {
        if (T[i] == town) {
            if (new_elapsed == -1) {
                new_elapsed = solve(S[i], money - Y[i], elapsed + M[i]);
            } else {
                new_elapsed = compare(solve(S[i], money - Y[i], elapsed + M[i]), new_elapsed);
            }
            continue;
        } 
    }
    return new_elapsed;
}

int main() {
    std::cin >> N >> C >> V;
    S.resize(V);
    T.resize(V);
    Y.resize(V);
    M.resize(V);
    for (int i = 0; i < V; i++) {
        std::cin >> S[i];
    }
    for (int i = 0; i < V; i++) {
        std::cin >> T[i];
    }
    for (int i = 0; i < V; i++) {
        std::cin >> Y[i];
    }
    for (int i = 0; i < V; i++) {
        std::cin >> M[i];
    }
    std::cout << solve(N, C, 0) << std::endl;
}