//#include <bits/stdc++.h>
#include "bits/stdc++.h"
using namespace std;
typedef long long ll;


#include "boost/multiprecision/cpp_int.hpp"
#include "boost/multiprecision/cpp_dec_float.hpp"
namespace mp = boost::multiprecision;
typedef mp::cpp_int LL;
typedef mp::number<mp::cpp_dec_float<1024>> DD;// 仮数部が1024ビットの浮動小数点数型(TLEしたら小さくする)


typedef long double dd;
#define i_7 (ll)(1E9+7)
//#define i_7 998244353
#define i_5 i_7-2
ll mod(ll a){
    ll c=a%i_7;
    if(c>=0)return c;
    return c+i_7;
}
typedef pair<ll,ll> l_l;
typedef pair<dd,dd> d_d;
ll inf=(ll)1E16;
#define rep(i,l,r) for(ll i=l;i<=r;i++)
#define pb push_back
ll max(ll a,ll b){if(a<b)return b;else return a;}
ll min(ll a,ll b){if(a>b)return b;else return a;}
void Max(ll &pos,ll val){pos=max(pos,val);}//Max(dp[n],dp[n-1]);
void Min(ll &pos,ll val){pos=min(pos,val);}
void Add(ll &pos,ll val){pos=mod(pos+val);}
dd EPS=1E-9;
#define fastio ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define fi first
#define se second
#define endl "\n"
#define SORT(v) sort(v.begin(),v.end())
#define ERASE(v) v.erase(unique(v.begin(),v.end()),v.end())
#define POSL(v,x) (lower_bound(v.begin(),v.end(),x)-v.begin())
#define POSU(v,x) (upper_bound(v.begin(),v.end(),x)-v.begin())
template<class T,class S>
inline bool chmax(T &a, S b) {
    if(a < b) {
        a = b;
        return true;
    }
    return false;
}
template<class T,class S>
inline bool chmin(T &a, S b) {
    if(a > b) {
        a = b;
        return true;
    }
    return false;
}

void mod_print(ll k){
    ll P=1000;
    rep(y,1,P){
        ll x=mod(y*k);
        if(x+P>=i_7){
            x-=i_7;
        }
        if(abs(x)<=P){
            cout<<x<<"/"<<y<<endl;
            return;
        }
    }
    cout<<"nun"<<endl;
}
#define all(c) c.begin(),c.end()
//////////////////////////


const ll MOD=998244353;
template< ll mod >
struct NumberTheoreticTransform {

  vector< ll > rev, rts;
  ll base, max_base, root;

  NumberTheoreticTransform() : base(1), rev{0, 1}, rts{0, 1} {
    assert(mod >= 3 && mod % 2 == 1);
    auto tmp = mod - 1;
    max_base = 0;
    while(tmp % 2 == 0) tmp >>= 1, max_base++;
    root = 2;
    while(mod_pow(root, (mod - 1) >> 1) == 1) ++root;
    assert(mod_pow(root, mod - 1) == 1);
    root = mod_pow(root, (mod - 1) >> max_base);
  }

  inline ll mod_pow(ll x, ll n) {
    ll ret = 1;
    while(n > 0) {
      if(n & 1) ret = mul(ret, x);
      x = mul(x, x);
      n >>= 1;
    }
    return ret;
  }

  inline ll inverse(ll x) {
    return mod_pow(x, mod - 2);
  }

  inline ll add(ll x, ll y) {
    x += y;
    if(x >= mod) x -= mod;
    return x;
  }

  inline ll mul(ll a, ll b) {
    return 1ull * a * b % mod;
  }

  void ensure_base(ll nbase) {
    if(nbase <= base) return;
    rev.resize(1 << nbase);
    rts.resize(1 << nbase);
    for(ll i = 0; i < (1 << nbase); i++) {
      rev[i] = (rev[i >> 1] >> 1) + ((i & 1) << (nbase - 1));
    }
    assert(nbase <= max_base);
    while(base < nbase) {
      ll z = mod_pow(root, 1 << (max_base - 1 - base));
      for(ll i = 1 << (base - 1); i < (1 << base); i++) {
        rts[i << 1] = rts[i];
        rts[(i << 1) + 1] = mul(rts[i], z);
      }
      ++base;
    }
  }


  void ntt(vector< ll > &a) {
    const ll n = (ll) a.size();
    assert((n & (n - 1)) == 0);
    ll zeros = __builtin_ctzll(n);
    ensure_base(zeros);
    ll shift = base - zeros;
    for(ll i = 0; i < n; i++) {
      if(i < (rev[i] >> shift)) {
        swap(a[i], a[rev[i] >> shift]);
      }
    }
    for(ll k = 1; k < n; k <<= 1) {
      for(ll i = 0; i < n; i += 2 * k) {
        for(ll j = 0; j < k; j++) {
          ll z = mul(a[i + j + k], rts[j + k]);
          a[i + j + k] = add(a[i + j], mod - z);
          a[i + j] = add(a[i + j], z);
        }
      }
    }
  }


  vector< ll > multiply(vector< ll > a, vector< ll > b) {
    ll need = a.size() + b.size() - 1;
    ll nbase = 1;
    while((1 << nbase) < need) nbase++;
    ensure_base(nbase);
    ll sz = 1 << nbase;
    a.resize(sz, 0);
    b.resize(sz, 0);
    ntt(a);
    ntt(b);
    ll inv_sz = inverse(sz);
    for(ll i = 0; i < sz; i++) {
      a[i] = mul(a[i], mul(b[i], inv_sz));
    }
    reverse(a.begin() + 1, a.end());
    ntt(a);
    a.resize(need);
    return a;
  }
};
NumberTheoreticTransform<MOD> ntt;
////////////////////////////////////////////////////////////////////////////////
//vector<ll>a(2),b(3);
//rep(i,0,1)cin>>a[i];
//rep(i,0,2)cin>>b[i];
//auto c=ntt.multiply(a,b);
//for(auto x:c)cout<<x<<" ";cout<<endl;

ll n,s;
void conv(vector<ll>&ans){
    ll as=ans.size();
    while(as>s+1){
        ans.pop_back();
        as--;
    }
}
int main(){fastio
    cin>>n>>s;
    vector<ll>ans;
    ans.pb(1);
    rep(i,0,n-1){
        ll t;cin>>t;
        vector<ll>v(t+1);
        v[0]=2;v[t]=1;
        ans=ntt.multiply(ans,v);
        conv(ans);
    }
    //for(auto x:ans)cout<<x<<" ";cout<<endl;
    cout<<mod(ans[s])<<endl;
    
    return 0;
}





Measured memory_bytes: 3932