#include<cstdio>
#include<cstring>
#include<cctype>
#include<cmath>
#include<climits>
#include<algorithm>
#include<vector>
#include<valarray>
#include<string>
#include<set>
#include<map>
#include<stack>
#include<queue>
using namespace std;
  
  
#define rep(i,n) for(int i=0;i<n;i++)
#define REP(i,n) for(int i=1;i<=n;i++)
#define drep(i,n) for(int i=n-1;i>=0;i--)
#define DREP(i,n) for(int i=n;i>0;i--)
#define Rep(i,m,n) for(int i=m;i<n;i++)
#define scani(a) scanf("%d",&a)
#define scand(a) scanf("%lf",&a)
#define scans(s) scanf("%s",s)
#define printi(a) printf("%d",a)
#define prints(s) printf("%s",s)
#define even(n) (((n)+1)%2)
#define odd(n) ((n)%2)
#define sg(x) ((x)?1:0)
#define LF printf("\n")
#define SPACE printf(" ")
#define pb push_back
#define mp make_pair
#define bs binary_search
#define all(a) (a).begin(),(a).end()
#define MOD 100000007
  
typedef long long LL;
typedef vector<int> vi;
typedef vector<vector<int> > vvi;
typedef pair<double,double> pdd;
typedef pair<int,int> pii;
  
const double pi=acos(-1.0);
double rad(double t){return t*pi/180.0;}

int GCD(int x,int y){if(x<y)swap(x,y);if(x%y==0)return y;return GCD(y,x%y);}
int LCM(int x,int y){return x/GCD(x,y)*y;}

int n,c,v,s[1600],t[1600],y[1600],m[1600],path[60][60]={};

int dfs(int pos,int time,int cost){
  if(cost<0)return -1;
  if(pos==n)return time;
  int ret = -1;
  for(int i=pos+1;i<=n;i++){
    if(path[pos][i]){
      int temp=dfs(i,time+m[path[pos][i]],cost-y[path[pos][i]]);
      if(temp>=0){
	if(ret<0)ret=temp;
	else ret=min(ret,temp);
      }
    }
  }
  return ret;
}

int main(){
  scani(n);scani(c);scani(v);
  REP(i,v)scani(s[i]);REP(i,v)scani(t[i]);
  REP(i,v)scani(y[i]);REP(i,v)scani(m[i]);
  REP(i,v)path[s[i]][t[i]]=i;
  printi(dfs(1,0,c));
  LF;
  return 0;
}