#include <algorithm>
#include <cstdio>
#include <cstdlib>
#include <cctype>
#include <cmath>
#include <iostream>
#include <queue>
#include <list>
#include <map>
#include <numeric>
#include <set>
#include <sstream>
#include <string>
#include <vector>
using namespace std;
#define REP(i,a,n) for(int i=(a); i<(int)(n); i++)
#define rep(i,n) REP(i,0,n)
#define FOR(it,c) for(__typeof((c).begin()) it=(c).begin(); it!=(c).end(); ++it)
#define ALLOF(c) (c).begin(), (c).end()
typedef long long ll;

#define INF 1000000000

int Y[55][55];
int M[55][55];

struct ST {
  int pos;
  int cost;
  int sec;
};

int solve(int N, int C){
  ST st;
  st.pos = 1;
  st.cost = 0;
  st.sec = 0;
  vector<int> visited(N+1, INF);

  queue<ST> que; que.push(st);
  while(!que.empty()){
    st = que.front(); que.pop();
    if(visited[st.pos] < st.sec) continue;
    visited[st.pos] = st.sec;
    
    REP(i,1,N+1){
      if(Y[st.pos][i] != INF){
        ST nxt;
        nxt.pos = i;
        nxt.cost = st.cost + Y[st.pos][i];
        nxt.sec = st.sec + M[st.pos][i];
        if(nxt.cost > C) continue;
        que.push(nxt);
      }
    }    
  }
  if(visited[N] == INF) return -1;
  return visited[N];
}

int main(){
  int N, C, V, tmp;

  rep(i,55) rep(j,55){
    Y[i][j] = INF;
    M[i][j] = INF;
  }
  
  cin >> N >> C >> V;
  vector<int> S, T;
  rep(i,V){
    cin >> tmp;
    S.push_back(tmp);
  }
  rep(i,V){
    cin >> tmp;
    T.push_back(tmp);
  }
  rep(i,V){
    cin >> tmp;
    Y[S[i]][T[i]] = tmp;
  }
  rep(i,V){
    cin >> tmp;
    M[S[i]][T[i]] = tmp;
  }
  
  cout << solve(N, C) << endl;

  return 0;
}