#include <bits/stdc++.h>
using namespace std;
typedef signed long long ll;

#undef _P
#define _P(...) (void)printf(__VA_ARGS__)
#define FOR(x,to) for(x=0;x<(to);x++)
#define FORR(x,arr) for(auto& x:arr)
#define ITR(x,c) for(__typeof(c.begin()) x=c.begin();x!=c.end();x++)
#define ALL(a) (a.begin()),(a.end())
#define ZERO(a) memset(a,0,sizeof(a))
#define MINUS(a) memset(a,0xff,sizeof(a))
//-------------------------------------------------------

int N,C;
int W[51];
int A[51],B[51];
int memo[51][51][51];

int dp(int A,int B,int C) {
	if(C<=0) return 0;
	
	if(memo[A][B][C]>=0) return memo[A][B][C];
	memo[A][B][C]=0;
	int i;
	for(i=1;i<=50;i++) {
		if(A==i || B==i) continue;
		if(A) {
			if(A<B && B<i) continue;
			if(A>B && B>i) continue;
		}
		if(W[i]>C) continue;
		memo[A][B][C]=max(memo[A][B][C], i+dp(B,i,C-W[i]));
		
	}
	return memo[A][B][C];
	
}

void solve() {
	int i,j,k,l,r,x,y; string s;
	
	cin>>N>>C;
	FOR(i,51) W[i]=51;
	FOR(i,N) cin>>A[i];
	FOR(i,N) cin>>B[i];
	FOR(i,N) W[A[i]]=min(W[A[i]],B[i]);
	
	MINUS(memo);
	cout<<dp(0,0,C)<<endl;
}


int main(int argc,char** argv){
	string s;int i;
	if(argc==1) ios::sync_with_stdio(false), cin.tie(0);
	FOR(i,argc-1) s+=argv[i+1],s+='\n'; FOR(i,s.size()) ungetc(s[s.size()-1-i],stdin);
	cout.tie(0); solve(); return 0;
}