#include <iostream>

using namespace std;

int n, c;
int l[55], w[55];
int memo[55][55][55];

int calc(int x, int pp, int p)
{
	if(memo[x][pp][p] != -1) return memo[x][pp][p];
	
	int ret = 0;
	for(int i = 1; i <= n; i++){
		if(pp < p && l[i] > p) continue;
		if(pp > p && l[i] < p) continue;
		if(l[i] == p || l[i] == pp) continue;
		if(x+w[i] > c) continue;
		ret = max(ret, calc(x+w[i], p, l[i]) + l[i]);
	}
	return memo[x][pp][p] = ret;
}

bool check(int p, int q)
{
	int x = l[p], y = l[q];
	for(int i = 1; i <= n; i++){
		if(x == l[i] || y == l[i]) continue;
		if(w[p]+w[q]+w[i] > c) continue;
		if(x < y && y > l[i]) return true;
		if(x > y && y < l[i]) return true;
	}
	return false;
}

int main(void)
{
	cin >> n >> c;
	for(int i = 1; i <= n; i++) cin >> l[i];
	for(int i = 1; i <= n; i++) cin >> w[i];
	
	for(int i = 0; i < 55; i++){
		for(int j = 0; j < 55; j++){
			for(int k = 0; k < 55; k++){
				memo[i][j][k] = -1;
			}
		}
	}
	
	int ans = 0;
	for(int i = 1; i <= n; i++){
		for(int j = 1; j <= n; j++){
			if(l[i] == l[j]) continue;
			if(w[i]+w[j] > c) continue;
			if(!check(i, j)) continue;
			ans = max(ans, calc(w[i]+w[j], l[i], l[j]) + l[i]+l[j]);
		}
	}
	cout << ans << endl;
	return 0;
}