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

#define DEBUG(x) cout<<#x<<": "<<x<<endl;
#define DEBUG_VEC(v) cout<<#v<<":";for(int i=0;i<v.size();i++) cout<<" "<<v[i]; cout<<endl

typedef long long ll;
#define vi vector<int>
#define vl vector<ll>
#define vii vector< vector<int> >
#define vll vector< vector<ll> >
#define vs vector<string>
#define pii pair<int,int>
#define pis pair<int,string>
#define psi pair<string,int>
#define pll pair<ll,ll>
#define fi first
#define se second
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define rep1(i,n) for(int i=1;i<=(int)(n);i++)
#define all(c) c.begin(),c.end()
const int inf = 1000000001;
const ll INF = 2e18;
const ll MOD = 1000000007;
const ll mod = 1000000009;
const double pi = 3.14159265358979323846;
#define Sp(p) cout<<setprecision(15)<< fixed<<p<<endl;
int dx[4] = { 1,0,-1,0 }, dy[4] = { 0,1,0,-1 };
int dx2[8] = { 1,1,0,-1,-1,-1,0,1 }, dy2[8] = { 0,1,1,1,0,-1,-1,-1 };

int main() {
	int n, c, m;
	cin >> n >> c >> m;
	vi a(m), b(m), y(m), t(m);
	rep(i, m) {
		cin >> a[i];
		a[i]--;
	}
	rep(i, m) {
		cin >> b[i];
		b[i]--;
	}
	rep(i, m) {
		cin >> y[i];
	}
	rep(i, m) {
		cin >> t[i];
	}
	vll dp(n, vl(c + 1, INF));
	dp[0][0] = 0;
	rep(i, n) {
		rep(j, c + 1) {
			rep(k, m) {
				if (a[k] != i) {
					continue;
				}
				if (j + y[k] > c) {
					continue;
				}
				dp[b[k]][j + y[k]] = min(dp[b[k]][j + y[k]], dp[i][j] + t[k]);
			}
		}
	}
	ll ans = INF;
	rep(i, c + 1) {
		ans = min(ans, dp[n - 1][i]);
	}
	cout << ((ans >= INF)? -1:ans) << endl;
}