#include<bits/stdc++.h>
#include<atcoder/all>
using namespace std;
using namespace atcoder;
typedef long long int ll;
typedef long double ld;
typedef vector<ll> vi;
typedef vector<vi> vvi;
typedef vector<vvi> vvvi;
typedef vector<vvvi> vvvvi;
typedef pair<ll,ll> pi;
typedef pair<ll,pi> ppi;
typedef pair<ll,ppi> pppi;
typedef pair<ll,pppi> ppppi;
#define FOR(i,l,r) for(ll i=l;i<r;i++)
#define REP(i,n) FOR(i,0,n)
#define RFOR(i,l,r) for(ll i=r-1;i>=l;i--)
#define RREP(i,n) RFOR(i,0,n)
#define ALL(x) x.begin(),x.end()
#define F first
#define S second
#define BS(A,x) binary_search(ALL(A),x)
#define LB(A,x) (ll)(lower_bound(ALL(A),x)-A.begin())
#define UB(A,x) (ll)(upper_bound(ALL(A),x)-A.begin())
#define COU(A,x) (UB(A,x)-LB(A,x))
#define sz(c) ((ll)(c).size())
/*
#include<boost/multiprecision/cpp_int.hpp>
namespace mp=boost::multiprecision;
using Bint=mp::cpp_int;
*/
template<typename T>using min_priority_queue=priority_queue<T,vector<T>,greater<T>>;
template<typename T1,typename T2>ostream&operator<<(ostream&os,pair<T1,T2>&p){os<<p.F<<" "<<p.S;return os;}
template<typename T1,typename T2>istream&operator>>(istream&is,pair<T1,T2>&p){is>>p.F>>p.S;return is;}
template<typename T>ostream&operator<<(ostream&os,vector<T>&v){REP(i,sz(v))os<<v[i]<<(i+1!=sz(v)?" ":"");return os;}
template<typename T>istream&operator>>(istream&is,vector<T>&v){for(T&in:v)is>>in;return is;}
template<class T>bool chmax(T&a,T b){if(a<b){a=b;return 1;}return 0;}
template<class T>bool chmin(T&a,T b){if(b<a){a=b;return 1;}return 0;}
ld dist(ld x1,ld y1,ld x2,ld y2){return sqrtl((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));}
//*
using mint=modint998244353;
const ll mod=998244353;
const ld EPS=1e-8;
//*/
/*
using mint=modint1000000007;
const ll mod=1000000007;
//*/
//using mint=modint;
//*
typedef vector<mint> vm;
typedef vector<vm> vvm;
typedef vector<vvm> vvvm;
typedef vector<vvvm> vvvvm;
ostream&operator<<(ostream&os,mint&a){os<<a.val();return os;}
//*/
int main(){
  ll N,K;cin>>N>>K;
  vi A(N),C(N);cin>>A>>C;
  REP(i,N)A.emplace_back(A[i]);
  REP(i,N)C.emplace_back(C[i]);
  vector<vector<vector<bool>>>DP(2*N,vector<vector<bool>>(N+1,vector<bool>(51)));
  REP(i,2*N)DP[i][1][C[i]]=1;
  FOR(d,2,N+1){
  	REP(i,2*N+1-d)REP(c,51){
  		FOR(d1,1,d){
  			if(DP[i+d1][d-d1][c])FOR(c1,max(0LL,c-K),min(51LL,c+K+1))if(DP[i][d1][c1]){DP[i][d][c]=1;break;}
  			if(DP[i][d1][c])FOR(c1,max(0LL,c-K),min(51LL,c+K+1))if(DP[i+d1][d-d1][c1]){DP[i][d][c]=1;break;}
  			if(DP[i][d][c])break;
  		}
  	}
  }
  ll ans=0;
  REP(i,N)FOR(d,1,N+1){
  	ll s=0;
  	FOR(j,i,i+d)s+=A[j];
  	REP(c,51)if(DP[i][d][c])chmax(ans,s);
  }
  cout<<ans<<endl;
  return 0;
}