#include <iostream>
#include <utility>
#include <algorithm>
using namespace std;
#define rep(i,n) for(int i=0;i<n;i++)
#define INF 1<<25

int main(){
	int n,c,v;	cin>>n>>c>>v;
	int s[v],t[v],y[v],m[v];
	rep(i,v){
		cin>>s[i];	s[i]--;
	}
	rep(i,v){
		cin>>t[i];	t[i]--;
	}
	rep(i,v)	cin>>y[i];
	rep(i,v)	cin>>m[i];
	pair<int,int> map[n][n];
	rep(i,n){
		rep(j,n){
			map[i][j].first=INF;
			map[i][j].second=INF;
		}
	}
	rep(i,v){
		map[s[i]][t[i]].first=y[i];
		map[s[i]][t[i]].second=m[i];
	}
	int dp[n][c+1];
	rep(i,n){
		rep(j,c+1)	dp[i][j]=INF;
	}
	dp[0][c]=0;
	rep(i,n){
		rep(j,c+1){
			if(dp[i][j]==INF)	continue;
			rep(k,n){
				if(map[i][k].first==INF)	continue;
				int mon=j-map[i][k].first;
				if(mon<0)	continue;
				dp[k][mon]=min(dp[k][mon],dp[i][j]+map[i][k].second);
			}
		}
	}
	int ans=INF;
	rep(i,c+1)	ans=min(ans,dp[n-1][i]);
	if(ans==INF)	ans=-1;
	cout<<ans<<endl;
	return 0;
}