#include <bits/stdc++.h>
typedef long long ll;
#define FOR(i,a,b) for(ll i=(a);i<(b);i++)
#define REP(i,a) FOR(i,0,a)
	
using namespace std;
const ll MAX_L=50,MAX_C=50,MAX_N=50;
ll N,C,L[MAX_N],W[MAX_N];
ll dp[MAX_L+1][MAX_L+1][MAX_C+1];
ll dfs(ll l,ll m,ll c){
	if(dp[l][m][c]!=-1){
		return dp[l][m][c];
	}
	ll ret=0;
	REP(i,N){
		if(W[i]>c)continue;
		if(L[i]==l || L[i]==m)continue;
		if(m<min(L[i],l) || m>max(L[i],l)){
			ret=max(ret,dfs(m,L[i],c-W[i])+L[i]);
		}
	}
	return dp[l][m][c]=ret;
}
int main(){
	cin>>N>>C;
	REP(i,N){
		cin>>L[i];
	}
	REP(i,N)cin>>W[i];
	ll ans=0;
	memset(dp,-1,sizeof(dp));
	REP(i,N){
		if(W[i]>C)continue;
		ans=max(ans,L[i]);
		REP(j,N){
			if(L[i]==L[j]) continue;
			if(W[i]+W[j]>C) continue;
			ans=max(ans,L[i]+L[j]+dfs(L[i],L[j],C-W[i]-W[j]));
		}
	}
	
	cout<<ans<<endl;
}