#include <bits/stdc++.h>

using namespace std;

#define FOR(i, a, b) for(int i = (a); i < (b); i++)
#define RFOR(i, a, b) for(int i = (a) - 1; i >= (b); i--)
#define SZ(a) int(a.size())
#define ALL(a) a.begin(), a.end()
#define PB push_back
#define MP make_pair
#define F first
#define S second

typedef long long LL;
typedef vector<int> VI;
typedef pair<int, int> PII;
typedef double db;

const int mod = 998244353;

void updAdd(int& a, int b)
{
	a += b;
	if (a >= mod)
		a -= mod;
}

int add(int a, int b)
{
	return a + b < mod ? a + b : a + b - mod;
}

int mult(int a, int b)
{
	return (LL)a * b % mod;
}

int binpow(int a, int n)
{
	int res = 1;
	while (n)
	{
		if (n & 1)
			res = mult(res, a);
		a = mult(a, a);
		n >>= 1;
	}
	return res;
}

void solve()
{
	int n, T;
	cin >> n >> T;
	VI a(n), t(n);
	for (int& ai : a)
		cin >> ai;
	for (int& ti : t)
		cin >> ti;
	if (accumulate(ALL(t), 0LL) <= T)
	{
		int ans = 0;
		for (int ai : a)
			updAdd(ans, ai);
		FOR(i, 0, n)
			ans = mult(ans, 2);
		cout << ans << "\n";
		return;
	}
	int ans = 0;
	FOR(it, 0, 2)
	{
		VI cnt(T + 1), sum(T + 1);
		cnt[0] = 1;
		LL sumt = accumulate(ALL(t), 0LL), suma = accumulate(ALL(a), 0LL);
		FOR(i, 0, n)
		{
			sumt -= t[i];
			suma -= a[i];
			if (it == 0)
			{
				int cur = 0;
				FOR(j, T - t[i] + 1, T + 1)
				{
					updAdd(cur, sum[j]);
				}
				updAdd(ans, mult(cur, binpow(2, n - i - 1)));
			}
			else
			{
				int cur = 0;
				FOR(j, max(0LL, T - sumt - t[i] + 1), T - sumt + 1)
				{
					updAdd(cur, add(mult(cnt[j], suma), sum[j]));
				}
				updAdd(ans, mult(cur, binpow(2, n - i - 1)));
			}
			RFOR(j, T - t[i] + 1, 0)
			{
				updAdd(cnt[j + t[i]], cnt[j]);
				updAdd(sum[j + t[i]], add(sum[j], mult(a[i], cnt[j])));
			}
		}
	}
	cout << ans << "\n";
}

int main()
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	solve();
	return 0;
}