#include <algorithm>
#include <cstdio>
#include <iostream>
#include <map>
#include <math.h>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>
using namespace std;

#define ll long long
#define INF (1 << 30)
#define INFLL (1LL << 60)

int n,c,v;
vector<pair<int,pair<int,int> > > edge[1501];

int djikstra(){
	priority_queue<pair<int, pair<int,int> > > que;
	que.push(make_pair(0, make_pair(c,0)));

	//bool used[51] = {};

	while(que.size()){
		pair<int,pair<int,int> > data = que.top();
		que.pop();
		int nowTime = -data.first;
		int nowCost = data.second.first;
		int now = data.second.second;

		if(now == n - 1){
			return nowTime;
		}
		// if(used[now]) continue;
		// used[now] = true;

		for(int i = 0;i < edge[now].size();i++){
			int toTime = edge[now][i].first;
			int to = edge[now][i].second.first;
			int toCost = edge[now][i].second.second;
			if(nowCost - toCost < 0) continue;
			que.push(make_pair(-(nowTime + toTime), make_pair(nowCost - toCost, to)));
		}
	}
	return -1;
}

int main() {
	cin >> n >> c >> v;
	int s[1501],t[1501],y[1501],m[1501];
	for(int i = 0;i < v;i++){
		cin >> s[i];
		s[i]--;
	}
	for(int i = 0;i < v;i++){
		cin >> t[i];
		t[i]--;
	}
	for(int i = 0;i < v;i++){
		cin >> y[i];
	}
	for(int i = 0;i < v;i++){
		cin >> m[i];
	}
	for(int i = 0;i < v;i++){
		edge[s[i]].push_back(make_pair(m[i], make_pair(t[i], y[i])));
	}

	cout << djikstra() << endl;
	return 0;
}