import java.util.*;
public class Main{	
    public static void main(String[] args) {
    	Scanner sc = new Scanner(System.in); 
    	ArrayList<ArrayList<tpl>> List = new ArrayList<>();
    	ArrayList<tpl> triple = new ArrayList<>();
    	int town = sc.nextInt();
    	int money = sc.nextInt();
    	int ru = sc.nextInt();

    	int[] from = new int[ru];
    	int[] to = new int[ru];
    	int[] cost = new int[ru];
    	int[] time = new int[ru];

    	for(int i=0; i<ru ;i++){//入力
    		from[i] = sc.nextInt();
    	}
    	for(int i=0; i<ru ;i++){//入力
    		to[i] = sc.nextInt();
    	}
    	for(int i=0; i<ru ;i++){//入力
    		cost[i] = sc.nextInt();
    	}
    	for(int i=0; i<ru ;i++){//入力
    		time[i] = sc.nextInt();
    	}
    	
    	triple.add(new tpl(0,0,0));//初期位置 (from = 0)
    	ArrayList<tpl> copy = new ArrayList<>(triple);   	
    	List.add(copy);
    	triple.clear();
    	
    	for(int i=2; i<=town ;i++){//二番目の町から
    		for(int j=0; j<ru ;j++){
    		    if(to[j] == i){
                    ArrayList<tpl> sub = new ArrayList<>(List.get(from[j]-1));
    		    	for(int t=0; t<sub.size(); t++){
    		            triple.add(new tpl(from[j], cost[j] + sub.get(t).get_cost(),
    		            		       time[j] + sub.get(t).get_time()));   		    	    
    		    	}
    		    }
    		}
    		ArrayList<tpl> copy_2 = new ArrayList<>(triple);
    		List.add(copy_2);
    		triple.clear();
    	}
    	//最短経路を取り出す
    	triple = List.get(town-1);
    	if(triple.isEmpty()){
    		System.out.println(-1);
    	}else{
    	    int c;
    	    ArrayList<Integer> sort = new ArrayList();
    	    for(int i=0; i<triple.size(); i++){
    		    if(triple.get(i).get_cost() <= money){
    			    sort.add(triple.get(i).get_time());
    		    }
    		}
    	    if(sort.isEmpty()){
    	    	System.out.println(-1);
    	    }else{
    	        Collections.sort(sort);
    	        System.out.println(sort.get(0));
    	    }
    	}
    }
    
    public static class tpl{
    	int town_from;
    	int cost;
    	int time;
    	tpl(int from, int cost, int time){
    		this.town_from = from;
    		this.cost = cost;
    		this.time = time;
    	}
    	int get_cost(){
    		return cost;
    	}
    	int get_time(){
    		return time;
    	}
    }
}