#include <iostream>
#include <queue>
#include <map>
using namespace std;
struct Info{
        int from,to,cost,time;
};
struct Dik{
        int vertex;
        int cost,time;
//      bool operator<(const Dik &other)const{
//              return cost>other.cost;
//      }
};
int main(){
        int N,current,ver;
        cin >> N >> current;
        cin >> ver;
        Info info[2500];
        map<int,int> dp;
        for(int i=0 ; i<ver ; i++ ){
                cin >> info[i].from;
                dp[info[i].from]=1000000000;
        }
        for(int i=0 ; i<ver ; i++ ){
                cin >> info[i].to;
                dp[info[i].to]=1000000000;
        }
        for(int i=0 ; i<ver ; i++ )
                cin >> info[i].cost;
        for(int i=0 ; i<ver ; i++ )
                cin >> info[i].time;
        queue<Dik> circle;
        Dik now;now.vertex=1;
        now.cost=now.time=0;
        circle.push(now);
        int min=1000000000;
        while(circle.size()!=0){
                now=circle.front();circle.pop();
                if(now.cost>current)continue;
                if(now.vertex==N)
                        if(min>now.time)min=now.time;
                Dik next;
                if(min<now.time)continue;
//              if(dp[now.vertex]<now.time){
//                      cout << now.time<< endl;
//                      continue;
//              }
                dp[now.vertex]=now.time;
                for(int i=0 ; i<ver ; i++ ){
                        if(info[i].from==now.vertex){
                                next.vertex=info[i].to;
                                next.cost=now.cost+info[i].cost;
                                next.time=now.time+info[i].time;
                                circle.push(next);
                        }
                }
        }
        if(min==1000000000)
                cout<<-1<<endl;
        else
                cout << min << endl;
        return 0;
}