#include<stdio.h>

typedef unsigned short ushort;

struct city_info {
	ushort city_num;
	ushort money;
	ushort road_num;
	ushort S_city[1500];
	ushort T_city[1500];
	ushort cost[1500];
	ushort time[1500];
	unsigned int ans;
};

struct city_info city;

void numin(ushort index, ushort numBox[1500]) {
	char str;
	for (ushort i = 0; i<index; i++)
		numBox[i] = 0;
	ushort cnt = 0;
	while (cnt < index) {
		str = getchar();
		if (str == '\n' && cnt == 0)
			continue;
		else if (str == '\n' && cnt != 0)
			break;
		else if (str < '0' || str > '9')
			cnt++;
		else
			numBox[cnt] = numBox[cnt] * 10 + (ushort)str - (ushort)'0';
	}
}


int search(ushort S_num, ushort cost, ushort timer) {
	for (short i = 0;i < city.road_num; i++) {
		if (city.S_city[i] == S_num) {
			if (city.money >= cost + city.cost[i] && city.ans > timer + city.time[i]) {		// コストオーバーの場合は対象外
				if (city.T_city[i] == city.city_num)		// 町まで到着した場合
					city.ans = timer + city.time[i];
				else
					search(city.T_city[i], cost + city.cost[i], timer + city.time[i]);
			}
		}
	}
	return 0;
}

int main() {

	scanf("%d", &city.city_num);
	scanf("%d", &city.money);
	scanf("%d", &city.road_num);

	numin(city.road_num, city.S_city);
	numin(city.road_num, city.T_city);
	numin(city.road_num, city.cost);
	numin(city.road_num, city.time);

	city.ans = 1500001;

	search(1, 0, 0);

	if (city.ans == 1500001)
		printf("-1");
	else
		printf("%d", city.ans);

	return 0;
}