#include <iostream>
#include <algorithm>
#define INF (2 << 28)
using namespace std;

int n, c, v, dp[55][333];
int s[1511], t[1511], y[1511], m[1511];

int rec(int now, int cost){
  
  if(cost < 0) return INF;
  if(dp[now][cost]) return dp[now][cost];
  if(now == n) return 0;  

  int ret = INF;
  for(int i = 0; i < v; i++){
    if(s[i] == now){
      ret = min(ret, rec(t[i], cost - y[i]) + m[i]);
    }
  }
  return dp[now][cost] = ret;
}

int main(){
  
  cin >> n >> c >> v;
  for(int i = 0; i < v; i++) cin >> s[i];
  for(int i = 0; i < v; i++) cin >> t[i];
  for(int i = 0; i < v; i++) cin >> y[i];
  for(int i = 0; i < v; i++) cin >> m[i];
  
  int d;
  if((d = rec(1, c)) == INF) cout << -1 << endl;
  else cout << d << endl;

}