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(" "));//from
        int[] T = convert(br.readLine().split(" "));//to
        int[] Y = convert(br.readLine().split(" "));//費用
        int[] M = convert(br.readLine().split(" "));//時間

        int[][] min = new int[N + 1][C + 1];

        for (int i = 2; i <= N; i++) {
            Arrays.fill(min[i], Integer.MAX_VALUE);
        }

        for (int i = 1; i <= N; i++) {
            for (int j = 0; j < V; j++) {

                int tmpS = S[j];
                int tmpT = T[j];
                int tmpY = Y[j];
                int tmpM = M[j];

                for (int k = 0; k + tmpY <= C; k++) {

                    if (min[tmpS][k] != Integer.MAX_VALUE
                            && min[tmpS][k] + tmpM < min[tmpT][k + tmpY]) {

                        min[tmpT][k + tmpY] = min[tmpS][k] + tmpM;
                    }
                }
            }
        }

        int minTime = Integer.MAX_VALUE;

        for (int i = 0; i <= C; i++) {
            if (min[N][i] < minTime) {
                minTime = min[N][i];
            }
        }

        if (minTime == Integer.MAX_VALUE) {
            System.out.println(-1);
        } else {
            System.out.println(minTime);
        }
    }

    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;
    }
}