#include <bits/stdc++.h>
using namespace std;

typedef long long   signed int LL;
typedef long long unsigned int LU;

#define incID(i, l, r) for(int i = (l)    ; i <  (r); i++)
#define incII(i, l, r) for(int i = (l)    ; i <= (r); i++)
#define decID(i, l, r) for(int i = (r) - 1; i >= (l); i--)
#define decII(i, l, r) for(int i = (r)    ; i >= (l); i--)
#define  inc(i, n) incID(i, 0, n)
#define inc1(i, n) incII(i, 1, n)
#define  dec(i, n) decID(i, 0, n)
#define dec1(i, n) decII(i, 1, n)

#define inII(v, l, r) ((l) <= (v) && (v) <= (r))
#define inID(v, l, r) ((l) <= (v) && (v) <  (r))

#define PB push_back
#define EB emplace_back
#define MP make_pair
#define FI first
#define SE second
#define PQ priority_queue

#define  ALL(v)  v.begin(),  v.end()
#define RALL(v) v.rbegin(), v.rend()
#define  FOR(it, v) for(auto it =  v.begin(); it !=  v.end(); ++it)
#define RFOR(it, v) for(auto it = v.rbegin(); it != v.rend(); ++it)

template<typename T> bool   setmin(T & a, T b) { if(b <  a) { a = b; return true; } else { return false; } }
template<typename T> bool   setmax(T & a, T b) { if(b >  a) { a = b; return true; } else { return false; } }
template<typename T> bool setmineq(T & a, T b) { if(b <= a) { a = b; return true; } else { return false; } }
template<typename T> bool setmaxeq(T & a, T b) { if(b >= a) { a = b; return true; } else { return false; } }
template<typename T> T gcd(T a, T b) { return (b == 0 ? a : gcd(b, a % b)); }
template<typename T> T lcm(T a, T b) { return a / gcd(a, b) * b; }

// ---- ----

bool is_kado(LL a, LL b, LL c) { return (a != c && ((a < b && b > c) || (a > b && b < c))); }

int n, c, l[50], w[50], dp[51][51][51];

int main() {
	cin >> n >> c;
	inc(i, n) { cin >> l[i]; }
	inc(i, n) { cin >> w[i]; }
	
	incII(i, 0, 50) {
	incII(j, 0, 50) {
	incII(v, 0,  c) {
		dp[i][j][v] = -1;
	}
	}
	}
	
	inc(i, n) {
	inc(j, n) {
	inc(k, n) {
		if(w[i] + w[j] + w[k] <= c && is_kado(l[i], l[j], l[k])) {
			setmax(dp[l[j]][l[k]][w[i] + w[j] + w[k]], l[i] + l[j] + l[k]);
		}
	}
	}
	}
	
	bool f = true;
	while(f) {
		f = false;
		decII(i, 0, 50) {
		decII(j, 0, 50) {
		decII(v, 0,  c) {
			if(dp[i][j][v] < 0) { continue; }
			inc(k, n) {
				if(v + w[k] <= c && is_kado(i, j, l[k])) {
					f |= setmax(dp[j][l[k]][v + w[k]], dp[i][j][v] + l[k]);
				}
			}
		}
		}
		}
	}
	
	int ans = 0;
	incII(i, 0, 50) {
	incII(j, 0, 50) {
	incII(v, 0,  c) {
		setmax(ans, dp[i][j][v]);
	}
	}
	}
	
	cout << ans << endl;
	
	return 0;
}