#include <bits/stdc++.h>
using namespace std;

struct road {
	int s, t, y, m;
};
int main() {
	int n, c, v;
	cin >> n >> c >> v;
	vector<road> r(v);
	for (int i = 0;i < v;i++) {
		cin >> r[i].s;
	}
	for (int i = 0;i < v;i++) {
		cin >> r[i].t;
	}
	for (int i = 0;i < v;i++) {
		cin >> r[i].y;
	}
	for (int i = 0;i < v;i++) {
		cin >> r[i].m;
	}

	queue<road> q;
	q.push(road{ 0,1,0,0 });
	int mi = 1000000000;
	while (!q.empty()) {
		road qf = q.front();q.pop();
		for (int i = 0;i < v;i++) {
			if (qf.t == r[i].s) {
				if (qf.y+r[i].y <= c) {
					if (r[i].t == n) {
						mi = min(mi, qf.m+r[i].m);
					}
					else {
						q.push(road{ 0,r[i].t,qf.y + r[i].y,qf.m + r[i].m });
					}
				}
			}
		}
	}

	cout << ((mi == 1000000000) ? -1 : mi) << endl;



	return 0;
}