Problem:
Score : 600 points

Problem Statement

Given are a sequence of N positive integers A_1, A_2, \ldots, A_N and another positive integer S.

For a non-empty subset T of the set \{1, 2, \ldots , N \}, let us define f(T) as follows:

f(T) is the number of different non-empty subsets \{x_1, x_2, \ldots , x_k \} of T such that A_{x_1}+A_{x_2}+\cdots +A_{x_k} = S.

Find the sum of f(T) over all 2^N-1 subsets T of \{1, 2, \ldots , N \}. Since the sum can be enormous, print it modulo 998244353.

Constraints

All values in input are integers.

1 \leq N \leq 3000

1 \leq S \leq 3000

1 \leq A_i \leq 3000

Input

Input is given from Standard Input in the following format:

N S
A_1 A_2 ... A_N

Output

Print the sum of f(T) modulo 998244353.

Sample Input 1

3 4
2 2 4

Sample Output 1

6

For each T, the value of f(T) is shown below. The sum of these values is 6.

f(\{1\}) = 0

f(\{2\}) = 0

f(\{3\}) = 1 (One subset \{3\} satisfies the condition.)

f(\{1, 2\}) = 1 (\{1, 2\})

f(\{2, 3\}) = 1 (\{3\})

f(\{1, 3\}) = 1 (\{3\})

f(\{1, 2, 3\}) = 2 (\{1, 2\}, \{3\})

Sample Input 2

5 8
9 9 9 9 9

Sample Output 2

0

Sample Input 3

10 10
3 1 4 1 5 9 2 6 5 3

Sample Output 3

3296

Solution in C++ (GCC 9.2.1) (judge verdict: Accepted)

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

using ll = long long;
using Vi = vector<int>;
using Vl = vector<ll>;
using Pii = pair<int, int>;
using Pll = pair<ll, ll>;

constexpr int I_INF = numeric_limits<int>::max();
constexpr ll L_INF = numeric_limits<ll>::max();

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

template <std::int_fast64_t Modulus>
class ModInt {
    using i64 = std::int_fast64_t;

private:
    i64 m_value;

public:
    constexpr ModInt(const i64 x = 0) noexcept : m_value(x % Modulus) {
        if (m_value < 0) m_value += Modulus;
    }

    constexpr const i64& value() const noexcept { return m_value; }

    constexpr ModInt& operator+=(const ModInt rhs) noexcept {
        m_value += rhs.m_value;
        if (m_value >= Modulus) {
            m_value -= Modulus;
        }
        return *this;
    }
    constexpr ModInt& operator-=(const ModInt rhs) noexcept {
        if (m_value < rhs.m_value) {
            m_value += Modulus;
        }
        m_value -= rhs.m_value;
        return *this;
    }
    constexpr ModInt& operator*=(const ModInt rhs) noexcept {
        m_value = m_value * rhs.m_value % Modulus;
        return *this;
    }
    constexpr ModInt& operator/=(ModInt rhs) noexcept {
        i64 exp = Modulus - 2;
        while (exp) {
            if (exp & 1) {
                *this *= rhs;
            }
            rhs *= rhs;
            exp >>= 1;
        }
        return *this;
    }

    constexpr ModInt& operator++() noexcept {
        *this += 1;
        return *this;
    }
    constexpr ModInt operator++(int) noexcept {
        ModInt res = *this;
        *this += 1;
        return res;
    }
    constexpr ModInt& operator--() noexcept {
        *this -= 1;
        return *this;
    }
    constexpr ModInt operator--(int) noexcept {
        ModInt res = *this;
        *this -= 1;
        return res;
    }

    constexpr ModInt inv() const noexcept {
        i64 q = m_value;
        i64 b = Modulus, u = 1, v = 0;
        while (b) {
            i64 t = q / b;
            q -= t * b;
            std::swap(q, b);
            u -= t * v;
            std::swap(u, v);
        }
        u %= Modulus;
        if (u < 0) u += Modulus;
        return u;
    }

    constexpr ModInt pow(i64 k) const noexcept {
        ModInt res = 1;
        ModInt tmp;
        if (k < 0) {
            tmp = (*this).inv();
            k = -k;
        }
        else {
            tmp = *this;
        }
        for (; k > 0; k >>= 1) {
            if (k & 1) res *= tmp;
            tmp *= tmp;
        }
        return res;
    }

    friend constexpr ModInt operator+(const ModInt& lhs, const ModInt& rhs) noexcept {
        return ModInt<Modulus>(lhs) += rhs;
    }
    friend constexpr ModInt operator-(const ModInt& lhs, const ModInt& rhs) noexcept {
        return ModInt<Modulus>(lhs) -= rhs;
    }
    friend constexpr ModInt operator*(const ModInt& lhs, const ModInt& rhs) noexcept {
        return ModInt<Modulus>(lhs) *= rhs;
    }
    friend constexpr ModInt operator/(const ModInt& lhs, const ModInt& rhs) noexcept {
        return ModInt<Modulus>(lhs) /= rhs;
    }

    friend constexpr bool operator<(const ModInt& lhs, const ModInt& rhs) noexcept {
        return lhs.m_value < rhs.m_value;
    }
    friend constexpr bool operator>(const ModInt& lhs, const ModInt& rhs) noexcept {
        return lhs.m_value > rhs.m_value;
    }
    friend constexpr bool operator<=(const ModInt& lhs, const ModInt& rhs) noexcept {
        return lhs.m_value <= rhs.m_value;
    }
    friend constexpr bool operator>=(const ModInt& lhs, const ModInt& rhs) noexcept {
        return lhs.m_value >= rhs.m_value;
    }

    friend constexpr bool operator==(const ModInt& lhs, const ModInt& rhs) noexcept {
        return lhs.m_value == rhs.m_value;
    }
    friend constexpr bool operator!=(const ModInt& lhs, const ModInt& rhs) noexcept {
        return lhs.m_value != rhs.m_value;
    }

    friend std::istream& operator>>(std::istream& is, ModInt& rhs) {
        i64 a;
        is >> a;
        rhs = a;
        return is;
    }
    friend std::ostream& operator<<(std::ostream& os, const ModInt& rhs) {
        os << rhs.m_value;
        return os;
    }
};


constexpr ll MOD = 998244353;
using Mint = ModInt<MOD>;


Mint dp[3010][3010];

void solve() {
    ll N, S;
    cin >> N >> S;
    Vl A(N);
    for (ll i = 0; i < N; i++) {
        cin >> A[i];
    }

    dp[0][0] = Mint(2).pow(N);
    Mint t = Mint(2).inv();
    for (ll i = 0; i < N; i++) {
        for (ll j = 0; j <= 3000; j++) {
            if (j - A[i] >= 0) {
                dp[i + 1][j] += dp[i][j - A[i]] * t;
            }
            dp[i + 1][j] += dp[i][j];
        }
    }

    cout << dp[N][S] << "\n";
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

int main() {
#ifdef FASTIO
    cin.tie(0), cout.tie(0);
    ios::sync_with_stdio(false);
#endif
#ifdef FILEINPUT
    ifstream ifs("./in_out/input.txt");
    cin.rdbuf(ifs.rdbuf());
#endif
#ifdef FILEOUTPUT
    ofstream ofs("./in_out/output.txt");
    cout.rdbuf(ofs.rdbuf());
#endif
    solve();
    cout << flush;
    return 0;
}