#include "bits/stdc++.h"
using namespace std;
#define rt return
#define FOR(i,j,k) for(int i=j; i<(int)k;++i)
#define rep(i,j) FOR(i,0,j)
#define each(x,y) for(auto &(x):(y))
#define mp make_pair
#define mt make_tuple
#define all(x) (x).begin(),(x).end()
#define debug(x) cout<<#x<<": "<<(x)<<endl
#define smax(x,y) (x)=max((x),(y))
#define smin(x,y) (x)=min((x),(y))
#define MEM(x,y) memset((x),(y),sizeof (x))
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;

struct E{
    int fr, to, yen, mi;
};
const int N_MAX = 51, C_MAX = 301, M_MAX = 1501, INF = numeric_limits<int>::max();
int N, C, M;
int dp[N_MAX][C_MAX], ans=INF;
E ed[M_MAX];
vector<E> g[N_MAX];

int main(){
    ios::sync_with_stdio(0);
    cin.tie(0);
    cin >> N >> C >> M;
    rep(i, M)cin >> ed[i].fr;
    rep(i, M)cin >> ed[i].to;
    rep(i, M)cin >> ed[i].yen;
    rep(i, M)cin >> ed[i].mi;
    rep(i, M)
        g[ed[i].fr].push_back(ed[i]);
    rep(i, N_MAX)rep(j, C_MAX)dp[i][j] = INF;
    dp[1][0] = 0;
    rep(i, N)rep(j, C)if(dp[i][j] != INF){
        each(e, g[i]){
            int nj = j + e.yen;
            if(nj <= C)
                smin(dp[e.to][nj], dp[i][j] + e.mi);
        }
    }
    rep(i, C + 1)smin(ans, dp[N][i]);
    cout << (ans == INF ? -1 : ans) << endl;
}