import java.util.*;

public class Main {
	public static void main (String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int c = sc.nextInt();
		int size = sc.nextInt();
		int[] starts = new int[size];
		int[] ends = new int[size];
		int[] costs = new int[size];
		int[] times = new int[size];
		for (int i = 0; i < size; i++) {
		    starts[i] = sc.nextInt() - 1;
		}
		for (int i = 0; i < size; i++) {
		    ends[i] = sc.nextInt() - 1;
		}
		for (int i = 0; i < size; i++) {
		    costs[i] = sc.nextInt();
		}
		for (int i = 0; i < size; i++) {
		    times[i] = sc.nextInt();
		}
		ArrayList<ArrayList<Path>> graph = new ArrayList<>();
		for (int i = 0; i < n; i++) {
		    graph.add(new ArrayList<>());
		}
		for (int i = 0; i < size; i++) {
		    graph.get(starts[i]).add(new Path(ends[i], costs[i], times[i]));
		}
		PriorityQueue<Path> queue = new PriorityQueue<>();
		queue.add(new Path(0, c, 0));
		int[] values = new int[n];
		Arrays.fill(values, Integer.MAX_VALUE);
		while (queue.size() > 0) {
		    Path p = queue.poll();
		    if (values[p.idx] <= p.time) {
		        continue;
		    }
		    values[p.idx] = p.time;
		    for (Path x : graph.get(p.idx)) {
		        if (x.cost > p.cost) {
		            continue;
		        }
		        queue.add(new Path(x.idx, p.cost - x.cost, p.time + x.time));
		    }
		}
		if (values[n - 1] == Integer.MAX_VALUE) {
		    System.out.println(-1);
		} else {
		    System.out.println(values[n - 1]);
		}
	}
	
	static class Path implements Comparable<Path> {
	    int idx;
	    int cost;
	    int time;
	    
	    public Path(int idx, int cost, int time) {
	        this.idx = idx;
	        this.cost = cost;
	        this.time = time;
	    }
	    
	    public int compareTo(Path another) {
	        if (cost == another.cost) {
	            return time - another.time;
	        } else {
	            return another.cost - cost;
	        }
	    }
	}
}