// Author: ChungNotTrung;
// Created: 2024-08-26 12:18:53
// Problem: None
// Tag: None
// Source: None
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define db long double
#define int long long
#define fi first
#define se second
#define pb push_back
#define ii pair<int, int>
#define vi vector<int>
#define vii vector<ii>
#define vvi vector<vi>
#define vvvi vector<vvi>
#define All(x) x.begin(), x.end()
#define file(name) fopen(name ".inp", "r") ? freopen(name ".inp", "r", stdin), freopen(name ".out", "w", stdout) : 0
#define file_trau(name) fopen(name ".inp", "r") ? freopen(name ".inp", "r", stdin), freopen(name ".ans", "w", stdout) : 0
#define Faster ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0)
#define Run_time cerr << " Time : " << (1.0 * clock() / CLOCKS_PER_SEC) << " s.\n"
#define bit(i, n) (1ll && ((1ll << i) & (n)))
#define ONBIT(i, mask) ((1ll << i) | (mask))
#define OFFBIT(i, mask) ((~(1ll << i)) & (mask))
#define MASK(n) (1ll << (n))
#define cnt_bit(n) (__builtin_popcountll(n))
#define Lg2(n) (63 - __builtin_clzll(n))
#define rep(i, x, n) for (int i = x; i <= n; ++i)
#define repd(i, n, x) for (int i = n; i >= x; --i)
#define repv(i, n) for (auto &i : n)
#define as_vi(v, n, val) v.assign(n + 1, val)
#define as_vvi(v, n, m, val) v.assign(n + 1, vi(m + 1, val))
#define as_vvvi(v, n, m, k, val) v.assign(n + 1, vvi(m + 1, vi(k + 1, val)))
#define left(id) (id << 1ll)
#define right(id) (id << 1ll | 1)
mt19937 rd(chrono::steady_clock().now().time_since_epoch().count());
int rng(int l, int r) { return uniform_int_distribution<int>(l, r)(rd); }
vi dx{0, 0, 1, -1, 1, 1, -1, -1};
vi dy{1, -1, 0, 0, -1, 1, -1, 1};
template <class X, class Y>
bool maximize(X &a, const Y &b)
{
if (a < b)
return a = b, true;
return false;
}
template <class X, class Y>
bool minimize(X &a, const Y &b)
{
if (a > b)
return a = b, true;
return false;
}
const int base = 311;
const int nmax = 1e6 + 10;
const int oo = 1e18 + 100;
const int MOD = 1e9 + 7;
int sqr(int x)
{
return x * x;
}
int POW(int a, int n)
{
int res = 1;
while (n > 0)
{
if (n % 2 == 1)
res = (res * a) % MOD;
a = (a * a) % MOD;
n /= 2;
}
return res;
}
void fixmod(int &val)
{
if (val < 0)
val = (val + MOD * MOD) % MOD;
if (val >= MOD)
val %= MOD;
}
int ntest;
int n,k,r;
int a[nmax],d[nmax],pos[nmax];
namespace sub1{
int pf[nmax];
int sum(int l,int r){
return pf[r]-pf[l-1];
}
void solve(){
rep(i,1,n){
pf[i]=pf[i-1]+a[i];
}
int left=1,right=1;
int ans=0;
rep(i,1,n){
while(pos[i]-pos[left]>r) left++;
while(pos[right]-pos[i]<=r&&right<n) right++;
if(pos[right]-pos[i]>r) right--;
maximize(ans,sum(left,right));
}
cout << ans;
}
}
namespace trau{
int p[nmax],pf[nmax];
ii f[nmax];
int sum(int l,int r){
return pf[r]-pf[l-1];
}
int next(int id){
if(id>n) return n;
int l=id,h=n;
while(l<=h){
int mid=l+h>>1;
if(pos[mid]-pos[id]>r){
h=mid-1;
}
else
{
l=mid+1;
}
}
return h;
}
// fi kq
// se cnt
int dp(int id,int cnt){
if(cnt==0||id>=n) return id;
int res=0;
if(f[id].fi!=0){
if(cnt==f[id].se){
res=f[id].fi;
}
else
{
res=dp(p[p[f[id].fi+1]],cnt-f[id].se-1);
}
}
else
{
res=dp(p[p[id+1]],cnt-1);
}
f[id]={res,cnt};
return res;
}
void solve(){
pos[n+1]=oo;
rep(i,1,n+3){
p[i]=next(i);
pf[i]=pf[i-1]+a[i];
}
int ans=0;
rep(i,1,n){
int j=dp(p[p[i]],k-1);
maximize(ans,sum(i,j));
// cout << i << ' ' << j << ' ' << sum(i,j) << '\n';
}
cout << ans;
}
}
void TryHard()
{
cin >> n >> k >> r;
rep(i,1,n-1){
cin >> d[i];
}
pos[1]=0;
rep(i,2,n){
pos[i]=pos[i-1]+d[i-1];
}
// rep(i,1,n){
// cout << pos[i] << ' ';
// }
// cout << "\n\n";
rep(i,1,n){
cin >> a[i];
}
// cout << '\n';
// if(k==1)
// sub1::solve();
// else
trau::solve();
}
main()
{
// Learning is like rowing upstream, not to advance is to drop back .
// A winner never stops trying .
Faster;
// file("SPACE");
// file_trau("");
ntest = 1;
while (ntest--)
{
TryHard();
cout << "\n";
}
}
// LIMIT :
