#include<bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
#define int long long
#define FOR(i,a) for(int i=0;i<(a);i++)
#define FORE(i,a,b) for(int i=(a);i<(b);i++)
#define sp <<' '<<
#define fi first
#define se second
#define pb push_back
typedef vector<int> vi;
typedef pair<int,int> pii;
typedef vector<pii> vii;
typedef vector<bool> vb;
typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> oset;
#define all(x) x.begin(),x.end()
#define cont(x) for(auto el:x) cout<<el<<' ';cout<<endl;
#define contp(x) for(auto el:x) cout<<el.fi<<'-'<<el.se<<' ';cout<<endl;
#define DEBUG(x) cout<<#x sp x<<endl;
#define carp(a,b) ((a%MOD)*(b%MOD))%MOD
#define topla(a,b) ((a%MOD)+(b%MOD))%MOD
#define mid (l+r)/2
const int MAXN=205;
const int MAXK=25;
const int MOD=1e9+7;
const int INF=1e18;
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(0);cout.tie(0);
//freopen("out.txt","w",stdout);
int n,l;
cin>>n>>l;
vi x(n+1), t(n+1);
FORE(i,1,n+1) cin>>x[i];
FORE(i,1,n+1) cin>>t[i];
vii vec;
FORE(i,1,n+1){
vec.pb({x[i],t[i]});
}
sort(all(vec));
int res=0;
do{
int cur=0;
int pos=0;
int ans=0;
for(auto el:vec){
int deg=abs(el.fi-pos);
deg=min(deg,abs(l-deg));
cur+=deg;
pos=el.fi;
if(cur<=el.se) ans++;
}
res=max(res,ans);
}while(next_permutation(all(vec)));
cout<<res<<endl;
}
