import java.io.*;
import java.util.*;

public class Main {

    public static void main(String[] args) throws Exception {

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        int N = Integer.parseInt(br.readLine());
        int C = Integer.parseInt(br.readLine());
        int V = Integer.parseInt(br.readLine());

        int[] S = convert(br.readLine().split(" "));
        int[] T = convert(br.readLine().split(" "));
        int[] Y = convert(br.readLine().split(" "));
        int[] M = convert(br.readLine().split(" "));

        int[][] cost = new int[N + 1][N + 1];
        int[][] time = new int[N + 1][N + 1];

        //経路形成（単方向）
        for (int i = 0; i < V; i++) {
            cost[S[i]][T[i]] = Y[i];
            time[S[i]][T[i]] = M[i];
        }

        ArrayList<int[]> next = new ArrayList();
        for (int i = 2; i <= N; i++) {
            if (cost[1][i] != 0) {
                int[] tmp = new int[4];

                tmp[0] = 1;
                tmp[1] = i;
                tmp[2] = cost[1][i];
                tmp[3] = time[1][i];

                next.add(tmp);
            }
        }

        next.sort(new CustomComparator());

        int[] minCost = new int[N + 1];
        int[] minTime = new int[N + 1];

        Arrays.fill(minCost, Integer.MAX_VALUE);
        Arrays.fill(minTime, Integer.MAX_VALUE);

        minCost[1] = 0;
        minTime[1] = 0;

        while (!next.isEmpty()) {
            int[] tmp = next.get(0);
            next.remove(0);

            if (minCost[tmp[0]] + tmp[2] <= C) {
                minCost[tmp[1]] = minCost[tmp[0]] + tmp[2];
                minTime[tmp[1]] = minTime[tmp[0]] + tmp[3];

                for (int i = 1; i <= N; i++) {

                    if (cost[tmp[1]][i] != 0) {
                        int[] tmp2 = new int[4];

                        tmp2[0] = tmp[1];
                        tmp2[1] = i;
                        tmp2[2] = cost[tmp[1]][i];
                        tmp2[3] = time[tmp[1]][i];

                        next.add(tmp2);
                    }
                }

                next.sort(new CustomComparator());
            }
        }

        if (minCost[N] <= C) {
            System.out.println(minTime[N]);
        } else {
            System.out.println(-1);
        }
    }

    private static int[] convert(String[] source) {
        int[] dest = new int[source.length];

        for (int i = 0; i < source.length; i++) {
            dest[i] = Integer.parseInt(source[i]);
        }

        return dest;
    }

    static class CustomComparator implements Comparator<int[]> {

        @Override
        public int compare(int[] a, int[] b) {
            int no1 = a[2];
            int no2 = b[2];

            if (no1 > no2) {
                return 1;

            } else if (no1 == no2) {
                return 0;

            } else {
                return -1;

            }
        }

    }
}