// #include <bits/stdc++.h>
#include <cstdio>
#include <algorithm>

#define INF (1 << 26)
using namespace std;

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

  scanf("%d", &N);
  scanf("%d", &C);
  scanf("%d", &V);
  int S[V], T[V], Y[V], M[V];

  for (int i = 0; i < V; i++) {
    scanf("%d", &S[i]);
  }

  for (int i = 0; i < V; i++) {
    scanf("%d", &T[i]);
  }

  for (int i = 0; i < V; i++) {
    scanf("%d", &Y[i]);
  }

  for (int i = 0; i < V; i++) {
    scanf("%d", &M[i]);
  }

  long dp[N + 1][C + 1];

  for (int i = 0; i < N + 1; i++) {
    for (int j = 0; j < C + 1; j++) {
      dp[i][j] = INF;
    }
  }
  dp[1][C] = 0;

  for (int i = 0; i < V; i++) {
    for (int j = 0; j < C + 1; j++) {
      if (0 <= j - Y[i]) {
        dp[T[i]][j - Y[i]] = min(dp[T[i]][j - Y[i]], dp[S[i]][j] + M[i]);
      }
    }
  }

  long min_time = INF;

  for (int i = 0; i < C + 1; i++) {
    min_time = min(min_time, dp[N][i]);
  }

  if (min_time == INF) {
    printf("-1\n");
  } else {
    printf("%ld\n", min_time);
  }
  return 0;
}