wspl09876twopoint

#include<cstdio>
#include<iostream>
using namespace std;
#define for(i,n) for(int i=1;i<=n;i++)
#define  D "%d"
#define prf printf
#define scf scanf
int n;int max1=-999,m,s[1999],s2[1999];
int a[1999],b[1999],c[1999],d[1999];
int main()
{
	scf(D D,&n,&m); 
	for(i,n)
	scf(D,&a[i]);
	for(i,n)
	scf(D,&b[i]);
	for(i,n)
	{
		scf(D,&c[i]);
		s[i]=max(s[i-1],c[i]);
	}
	for(i,n)
	{
		scf(D,&d[i]); 
		s2[i]=max(s2[i-1],d[i]);
	}
	int t=n;
	for(i,n)
	{
		while(a[i]+b[t]>m&&t>0)
		t--;
		if(t==0) break;
		max1=max(max1,s[i]+s2[t]);
	}
	prf(D,max1);
}