#include <iostream>
#include <vector>
#include <algorithm>
#include <queue>
using namespace std;

struct Edge {
    int to, money, time;
};

// priority_queueで使うための状態. 時間が小さい方から出てくる.
struct State {
    int city, money, time;

    bool operator>(const State& s) const {
        return time > s.time;
    }
};

const int kINF = 1 << 28;
const int kMAX_V = 60;
const int kMAX_C = 310;
const int kMAX_E = 1510;

vector<Edge> graph[kMAX_V];

int C, V, E;
int S[kMAX_E], T[kMAX_E], Y[kMAX_E], M[kMAX_E]; // 始点, 終点, コスト, 時間

int cost[kMAX_V][kMAX_C];   // (都市, 使った料金)

// この関数内で出力
void Dijkstra(int s) {
    fill((int* )cost, (int* )(cost + kMAX_V), kINF);
    cost[s][0] = 0;

    priority_queue<State, vector<State>, greater<State> > que;
    que.push((State){s, 0, 0}); // (city, money, time)
    while (!que.empty()) {
        State s = que.top(); que.pop();

        if (s.city == V - 1) {
            cout << cost[s.city][s.money] << endl;
            return;
        }

        if (cost[s.city][s.money] < s.time) continue;

        for (int i = 0; i < graph[s.city].size(); i++) {
            Edge e = graph[s.city][i];
            if (s.money + e.money <= C &&
                    cost[e.to][s.money + e.money] > s.time + e.time) {
                cost[e.to][s.money + e.money] = s.time + e.time;
                que.push((State){e.to, s.money + e.money, s.time + e.time});
            }
        }
    }
    cout << -1 << endl;
}

void Solve() {
    for (int i = 0; i < E; i++) {
        graph[S[i] - 1].push_back((Edge){T[i] - 1, Y[i], M[i]});
    }

    Dijkstra(0);
}

int main() {
    cin >> V >> C >> E;

    for (int i = 0; i < E; i++) {
        cin >> S[i];
    }
    for (int i = 0; i < E; i++) {
        cin >> T[i];
    }
    for (int i = 0; i < E; i++) {
        cin >> Y[i];
    }
    for (int i = 0; i < E; i++) {
        cin >> M[i];
    }

    Solve();

    return 0;
}