#include <bits/stdc++.h>
using namespace std;
#define REP(i,n) for(int i=0;i<(int)(n);i++)

int n,c;
int l[52], w[52];

int dp[52][4][52][52];
const int INF = 252521;

int main(){
    scanf("%d%d",&n,&c);
    REP(i,n)scanf("%d",l+i);
    REP(i,n)scanf("%d",w+i);
    REP(i,52)REP(f,4)REP(j,52)REP(k,52)dp[i][f][j][k] = -INF;
    dp[0][0][0][51] = dp[0][0][51][0] = 0;
    REP(sw,c)REP(f,4)REP(b2,52)REP(b1,52)if(dp[sw][f][b2][b1]>=0){
        REP(i,n){
            if(b2==b1 || b2==l[i] || b1==l[i])continue;
            if(b2<b1 && b1<l[i])continue;
            if(b2>b1 && b1>l[i])continue;
            int nw = sw + w[i];
            if(nw>c)continue;
            int nf = min(3,f+1);
            dp[nw][nf][b1][l[i]] = max(dp[nw][nf][b1][l[i]], dp[sw][f][b2][b1] + l[i]);
        }
    }
    int ans = 0;
    REP(i,c+1)REP(j,50)REP(k,50)ans = max(ans, dp[i][3][j+1][k+1]);
    printf("%d\n",ans);
    return 0;
}