////
////  main.cpp
////  Q17
////
////  Created by AkihiroKOBAYASHI on 7/15/15.
////  Copyright (c) 2015 Akhr5884. All rights reserved.
////

#include <iostream>

int n, c, v;
int s[1600],t[1600],y[1600],m[1600];
int temp[51][51];

int totaltime= -1;


void search(int start, int money, int time) {
    
    int count;
    
    if(totaltime == -1 || time < totaltime) {
        if(start == n) {
            if(totaltime == -1) {
                totaltime = time;
            }
            else {
                totaltime = time;
            }
        }
        else {
            for(count = 0; count < v; count++) {
                if(s[count] == start && money -  y[count] >= 0) {
                    search(t[count], money - y[count], time + m[count]);
                }
            }
        }
    }
    return;
}

int main(int argc, const char * argv[]) {

    std::cin >> n >> c >> v;
    
    int count, countA;
    
    for(count = 0; count < v; count++) {
        std::cin >> s[count];
    }

    for(count = 0; count < v; count++) {
        std::cin >> t[count];
    }

    for(count = 0; count < v; count++) {
        std::cin >> y[count];
    }

    for(count = 0; count < v; count++) {
        std::cin >> m[count];
    }
    
    for(count = 0; count < 51; count++) {
        for(countA = 0; countA < 51; countA++) {
            temp[count][countA] = -1;
        }
    }
    
    search(1, c, 0);
    
    std::cout << totaltime << "\n";

    return 0;
}