#include <bits/stdc++.h>
#define ff first
#define ss second
#define endl '\n'
using namespace std;
const long long INF = (long long) 1e18;
const int mod = (int) 1e9+7;
const int MAXN = (int) 405;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
ll n, l;
pii stm[MAXN];
int x[MAXN], t[MAXN];
int dp[MAXN][MAXN][205][2];
int main(){
ios_base::sync_with_stdio(false);
cin.tie(nullptr);cout.tie(nullptr);
#ifdef Local
freopen("C:/Users/Admin/Desktop/Yazilim/C/IO/int.txt","r",stdin);
freopen("C:/Users/Admin/Desktop/Yazilim/C/IO/out.txt","w",stdout);
#endif
cin>>n>>l;
for(int i = 0; i < n; i++) {
cin>>x[2*i];
x[2*i + 1] = x[2*i] - l;
}
stm[2*n] = {0, 0};
for(int i = 0; i < n; i++){
cin>>t[i];
stm[2*i] = {x[2*i], t[i]};
stm[2*i + 1] = {x[2*i + 1], t[i]};
}
sort(stm, stm + 2*n + 1);
int idx = 0;
for(int i = 0; i <= 2*n; i++){
if(stm[i] == make_pair(0, 0))
idx = i;
//cout<<stm[i].ff<<" "<<stm[i].ss<<endl;
}
memset(dp, 0x7f, sizeof(dp));
dp[idx][idx][0][0] = dp[idx][idx][0][1] = 0;
int ans = 0;
for(int i = 2; i <= n + 1; i++){
for(int j = idx - i + 1; j <= idx; j++){
dp[j][j + i - 1][0][0] = 2*stm[j + i - 1].ff - stm[j].ff;
dp[j][j + i - 1][0][1] = -2*stm[j].ff + stm[j + i - 1].ff;
for(int l = 1; l <= i; l++){
int &r = dp[j][j + i - 1][l][0];
r = min(r, dp[j + 1][j + i - 1][l][0] + stm[j + 1].ff - stm[j].ff);
r = min(r, dp[j + 1][j + i - 1][l][1] + stm[j + i - 1].ff - stm[j].ff);
if(stm[j + 1].ff - stm[j].ff + dp[j + 1][j + i - 1][l - 1][0] <= stm[j].ss){
r = min(r, stm[j + 1].ff - stm[j].ff + dp[j + 1][j + i - 1][l - 1][0]);
}
if(dp[j + 1][j + i - 1][l - 1][1] + stm[j + i - 1].ff - stm[j].ff <= stm[j].ss){
r = min(r, dp[j + 1][j + i - 1][l - 1][1] + stm[j + i - 1].ff - stm[j].ff);
}
int &rr = dp[j][j + i - 1][l][1];
rr = min(rr, dp[j][j + i - 2][l][0] + stm[j + i - 1].ff - stm[j].ff);
rr = min(rr, dp[j][j + i - 2][l][1] + stm[j + i - 1].ff - stm[j + i - 2].ff);
if(dp[j][j + i - 2][l - 1][0] + stm[j + i - 1].ff - stm[j].ff <= stm[i + j - 1].ss){
rr = min(rr, dp[j][j + i - 2][l - 1][0] + stm[j + i - 1].ff - stm[j].ff);
}
if(dp[j][j + i - 2][l - 1][1] + stm[j + i - 1].ff - stm[j + i - 2].ff <= stm[i + j - 1].ss){
rr = min(rr, dp[j][j + i - 2][l - 1][1] + stm[j + i - 1].ff - stm[j + i - 2].ff);
}
if(r <= 2e9 || rr <= 2e9){
ans = max(ans, l);
}
}
}
}
ans = min((int)n, ans);
//cout<<dp[4][5][1][0]<<" "<<dp[4][5][1][1]<<endl;
cout<<ans<<endl;
#ifdef Local
cout<<endl<<fixed<<setprecision(2)<<1000.0 * clock() / CLOCKS_PER_SEC<< " milliseconds ";
#endif
}
