import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.PriorityQueue;
import java.util.Scanner;


public class Main {
	
	public static class State implements Comparable<State> {
		int node, cost, time;

		public State(int node, int cost, int time) {
			super();
			this.node = node;
			this.cost = cost;
			this.time = time;
		}

		public int compareTo(State o) {
			if(Integer.compare(this.time, o.time) != 0){
				return Integer.compare(this.time, o.time);
			}else if(Integer.compare(this.cost, o.cost) != 0){
				return Integer.compare(this.cost, o.cost);
			}else if(Integer.compare(this.node, o.node) != 0){
				return Integer.compare(this.node, o.node);
			}else{
				return 0;
			}
		}
	}
	
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		
		final int N = sc.nextInt();
		final int C = sc.nextInt();
		final int V = sc.nextInt();
		
		int[] S = new int[V];
		for(int i = 0; i < V; i++){
			S[i] = sc.nextInt() - 1;
		}
		
		int[] T = new int[V];
		for(int i = 0; i < V; i++){
			T[i] = sc.nextInt() - 1;
		}
		
		int[] Y = new int[V];
		for(int i = 0; i < V; i++){
			Y[i] = sc.nextInt();
		}
		
		int[] M = new int[V];
		for(int i = 0; i < V; i++){
			M[i] = sc.nextInt();
		}
		
		ArrayList<HashSet<Integer>> nexts = new ArrayList<HashSet<Integer>>();
		ArrayList<HashMap<Integer, Integer>> costs = new ArrayList<HashMap<Integer, Integer>>();
		ArrayList<HashMap<Integer, Integer>> times = new ArrayList<HashMap<Integer, Integer>>();
		for(int i = 0; i < N; i++){
			nexts.add(new HashSet<Integer>());
			costs.add(new HashMap<Integer, Integer>());
			times.add(new HashMap<Integer, Integer>());
		}
		
		for(int i = 0; i < V; i++){
			nexts.get(S[i]).add(T[i]);
			costs.get(S[i]).put(T[i], Math.min(Y[i], costs.get(S[i]).containsKey(T[i]) ? costs.get(S[i]).get(T[i]) : Integer.MAX_VALUE));
			times.get(S[i]).put(T[i], Math.min(M[i], times.get(S[i]).containsKey(T[i]) ? times.get(S[i]).get(T[i]) : Integer.MAX_VALUE));		
		}
		
		boolean[][] visited = new boolean[N][C + 1];
		PriorityQueue<State> queue = new PriorityQueue<State>();
		queue.add(new State(0, 0, 0));
		
		while(!queue.isEmpty()){
			final State state = queue.poll();
			
			if(visited[state.node][state.cost]){
				continue;
			}else{
				visited[state.node][state.cost] = true;
			}
			
			if(state.node == N - 1){
				System.out.println(state.time);
				return;
			}
			
			for(final int next : nexts.get(state.node)){
				final int next_cost = state.cost + costs.get(state.node).get(next);
				final int next_time = state.time + times.get(state.node).get(next);
				
				if(next_cost > C){
					continue;
				}else if(visited[next][next_cost]){
					continue;
				}
				
				queue.add(new State(next, next_cost, next_time));
			}
		}
		
		System.out.println(-1);
	}
	
}