#include <bits/stdc++.h>
using namespace std;
using i64 = long long;
using ll = long long;
#define pb emplace_back
#define X first
#define Y second
#define AI(i) begin(i), end(i)
template<class T> bool chmax(T &a, T b) { return a < b && (a = b, true);}
template<class T> bool chmin(T &a, T b) { return b < a && (a = b, true);}
#ifdef KEV
#define DE(args...) kout("[ " + string(#args) + " ] = ", args)
void kout() { cerr << endl; }
template<class T, class ...U> void kout(T a, U ...b) { cerr << a << ' ', kout(b...); }
template<class T> void debug(T l, T r) { while (l != r) cerr << *l++ << " \n"[l==r]; }
#else
#define DE(...) 0
#define debug(...) 0
#endif

const int MAX_N = 300010, MAX_K = 40;

ll add_v[MAX_K], add_w[MAX_K];

// [ l, r, value ]
// small comes out

set< tuple<ll,ll,ll> > pq[MAX_K];

int safe_lg(ll v) {
	return v == 0 ? -1 : __lg(v);
}
ll res;
void put(ll l, ll r, ll v) {
	chmax(res, v); 
	//chmax(l, 1ll);
	if (l > r) return;
	int k = safe_lg(l); 
	assert(k == safe_lg(r));

	ll nl = l - add_w[k], nr = r - add_w[k], nv = v - add_v[k];
	while (true) {
		auto it = pq[k].lower_bound({nl, -1, -1});
		if (it != end(pq[k])) {
			auto [pl, pr, pv] = *it;
      if (pl == nr+1 && pv == nv) {
        nr = pr;
        break;
      }

			if (nr >= pl) {
				if (nv >= pv) {
					pq[k].erase(it);
					if (pr > nr)
						pq[k].insert({nr+1, pr, pv});
				} else {
          if (nr > pr)
            put(pr+1 + add_w[k], r, v);
					nr = pl-1;
				}
			} else break; 
		} else break;
	}
	{
		auto it = pq[k].lower_bound({nl, -1, -1});
		if (it != begin(pq[k])) {
			--it;
			auto [pl, pr, pv] = *it;
			if (nl <= pr) {
				if (nv >= pv) {
					pq[k].erase(it);
					if (pl < nl)
						pq[k].insert({pl, nl-1, pv});
          if (pr > nr)
            pq[k].insert({nr+1, pr, pv});
				} else {
					nl = pr+1;
				}
			}
		}
	}

	if (nl <= nr)
		pq[k].insert({nl, nr, nv});
}
void chk(int k) {
	//DE(k);
	while (pq[k].size()) {
		auto [_l, _r, _v] = *pq[k].begin();
		ll l = _l + add_w[k], r = _r + add_w[k], v = _v + add_v[k];
		if (l >= (1ll << k)) break; 
		//DE(l, r, 1ll << k);
		pq[k].erase(pq[k].begin());
		if (l == 0) {
			chmax(res, v);
			if (r > l)
				pq[k].insert({_l+1, _r, _v});
			continue;
		}
		int nk = safe_lg(l);
		ll nr = min(r, (2ll << nk)-1);
		//DE(nr);
		put(l, nr, v);
		if (nr < r) {
			//assert(nr+1-add_w[k] <= _r);
			//put(nr+1, r, v);
			pq[k].insert({nr+1 - add_w[k], _r, _v});
			assert(nr+1 - add_w[k] <= _r);
		}
	}
}
void obo(int k, ll dv, ll more) {
	//DE("obo");
	while (pq[k].size()) {
		auto [_l, _r, _v] = *pq[k].rbegin();
		//DE(_l, _r, _v);
		ll l = _l + add_w[k], r = _r + add_w[k], v = _v + add_v[k];
		if (r < dv) break;
		pq[k].erase(prev(end(pq[k])));

		if (r == dv) {
			chmax(res, more + v);
			if (r > l)
				pq[k].insert({_l, _r-1, _v});
			continue;
		}
		int nk = safe_lg(r - dv);
		ll nr = r - dv;
		ll nl = max(l - dv, 1ll << nk);
		put(nl, nr, v + more);
		DE(l, r, v, dv, nl, nr);
		if (nl != l - dv) {
			
			pq[k].insert({_l, nl+dv-1 - add_w[k], _v});
			DE(_l, nl+dv-1 - add_w[k]);
			//DE(_l, nl-1-add_w[k]);
			assert(_l <= nl+dv-1-add_w[k]);
		}
	} 
}

void dd() {
	DE("DD--------------__");
	for (int i = 0;i < MAX_K;++i) if (pq[i].size()) {
		DE(i);
		for (auto [_l, _r, _v] : pq[i]) {
			DE(_l+add_w[i], _r+add_w[i], _v+add_v[i]);
		}
	}
}

ll brute(ll n, ll T, vector<ll> w, vector<ll> v) {
	ll ret = 0;
	for (int i = 1;i <= T;++i) {
		ll cw = 0, cv = 0;
		for (int j = 0;j < n;++j)
			if (cw + w[j] <= i)
				cw += w[j], cv += v[j];
		chmax(ret, cv);
	}
	return ret;
}

random_device rd;
mt19937 gen(rd());

int main() {
	ios_base::sync_with_stdio(0), cin.tie(0);
	int N;
	ll T;
	cin >> N >> T;
	vector<ll> w(N), v(N);
	for (auto &i : w) cin >> i;
	for (auto &i : v) cin >> i;


  //while (true) {
 //   memset(add_v, 0, sizeof(add_v));
 //   memset(add_w, 0, sizeof(add_w));
 //   for (int i = 0;i < MAX_K;++i)
 //     pq[i].clear();
 //   res = 0;
 //   N = 10, T = 20;


//    vector<ll> w(N), v(N);
//    for (auto &i : w) i = gen() % 10 + 1;
//    for (auto &i : v) i = gen() % 10 + 1;


    for (int i = 0;;++i) {
      ll l = 1ll << i, r = min(T, (1ll<<(i+1))-1);
      put(l, r, 0);
      if (r == T) break;
    }
    for (int i = 0;i < N;++i) {
      DE(w[i], v[i]);
      int k = safe_lg(w[i]);
      obo(k, w[i], v[i]);
      for (++k; k < MAX_K;++k) {
        add_v[k] += v[i];
        add_w[k] += -w[i];
        chk(k);
      }
      dd();
    }

    for (int k = 0;k < MAX_K;++k) {
      //DE(k);
      for (auto [_1, _2, _v] : pq[k])
        chmax(res, _v + add_v[k]);
    }
    cout << res << '\n';
//    DE(brute(N, T, w, v));
//    cout << N << ' ' << T << '\n';
//    for (int i = 0;i < N;++i)
//      cout << w[i] << ' ';
//    cout << '\n';
//    for (int i = 0;i < N;++i)
//      cout << v[i] << ' ';
//    cout << endl;
//        
//    assert(res == brute(N, T, w, v));
//    break;
//  }
//
}