#define print(x) printf("%d\n",x)

#include <algorithm>
#define REP(i,n) for(int i=0; i<(int)(n); i++)

#include <queue>
#include <cstdio>
inline int getInt(){ int s; scanf("%d", &s); return s; }

#include <set>

using namespace std;

int main(){
  const int n = getInt();
  const int c = getInt();
  const int v = getInt();

  vector<int> s(v);
  vector<int> t(v);
  vector<int> y(v);
  vector<int> m(v);

  REP(i,v) s[i] = getInt() - 1;
  REP(i,v) t[i] = getInt() - 1;
  REP(i,v) y[i] = getInt();
  REP(i,v) m[i] = getInt();

  vector<pair<pair<int, int>, pair<int, int> > > g(v);
  REP(i,v) g[i] = make_pair(make_pair(s[i], t[i]), make_pair(y[i], m[i]));
  sort(g.begin(), g.end());

  const int inf = 100000000;
  vector<vector<int> > dp(n, vector<int>(c + 1, inf));

  dp[0][c] = 0;
  REP(i,v){
    const int ss = g[i].first.first;
    const int tt = g[i].first.second;
    const int yy = g[i].second.first;
    const int mm = g[i].second.second;
    REP(j,c+1) if(dp[ss][j] != inf && j - yy >= 0){
      dp[tt][j - yy] = min(dp[tt][j - yy], dp[ss][j] + mm);
    }
  }

  int ans = inf;
  REP(i,c+1) ans = min(ans, dp[n - 1][i]);
  ans = (ans == inf ? -1 : ans);

  printf("%d\n", ans);

  return 0;
}