#include <iostream>
#include <cstring>
using namespace std;

#define N 50
#define C 300
#define M 1500

int n, c, m;
int sc[M], tc[M], fa[M], tm[M];
int rt[N+1][C+1];

#define INPUT(v, n) for (int i = 0; i < (n); i++ ) cin >> (v)[i];

unsigned int dfs(int no, int rc)
{
	if ( rc < 0 ) { return -1; }
	if ( rt[no-1][rc] != 0 ) { return rt[no-1][rc]; }
	if ( no == n ) { return 0; }
	unsigned int min = -1;
	for ( int i = 0; i < m; i++ ) {
		if ( sc[i] == no ) {
			auto x = dfs(tc[i], rc - fa[i]);
			if ( x != -1 ) {
				x += tm[i];
				min = x < min && x != -1 ? x : min;
			}
		}
	}
	rt[no-1][rc] = min;
	return min;
}

int main()
{
	cin >> n >> c >> m;
	INPUT(sc, m);
	INPUT(tc, m);
	INPUT(fa, m);
	INPUT(tm, m);

	cout << (int)dfs(1, c) << endl;

	return 0;
}