#include<bits/stdc++.h>
#include<atcoder/all>
#define rep(i,b) for(int i=0;i<b;i++)
#define rrep(i,b) for(int i=b-1;i>=0;i--)
#define rep1(i,b) for(int i=1;i<b;i++)
#define repx(i,x,b) for(int i=x;i<b;i++)
#define rrepx(i,x,b) for(int i=b-1;i>=x;i--)
#define fore(i,a) for(auto& i:a)
#define rng(x) (x).begin(), (x).end()
#define rrng(x) (x).rbegin(), (x).rend()
#define sz(x) ((int)(x).size())
#define pb push_back
#define fi first
#define se second
#define pcnt __builtin_popcountll

using namespace std;
using namespace atcoder;

using ll = long long;
using ld = long double;
template<typename T> using mpq = priority_queue<T, vector<T>, greater<T>>;
template<typename T> bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<typename T> bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
template<typename T> ll sumv(const vector<T>&a){ll res(0);for(auto&&x:a)res+=x;return res;}
bool yn(bool a) { if(a) {cout << "Yes" << endl; return true;} else {cout << "No" << endl; return false;}}
#define retval(x) {cout << #x << endl; return;}
#define cout2(x,y) cout << x << " " << y << endl;
#define coutp(p) cout << p.fi << " " << p.se << endl;
#define out cout << ans << endl;
#define outd cout << fixed << setprecision(20) << ans << endl;
#define outm cout << ans.val() << endl;
#define outv fore(yans , ans) cout << yans << "\n";
#define outdv fore(yans , ans) cout << yans.val() << "\n";
#define coutv(v) {fore(vy , v) {cout << vy << " ";} cout << endl;}
#define coutv2(v) fore(vy , v) cout << vy << "\n";
#define coutvm(v) {fore(vy , v) {cout << vy.val() << " ";} cout << endl;}
#define coutvm2(v) fore(vy , v) cout << vy.val() << "\n";
using pll = pair<ll,ll>;using pil = pair<int,ll>;using pli = pair<ll,int>;using pii = pair<int,int>;using pdd = pair<ld,ld>;
using vi = vector<int>;using vd = vector<ld>;using vl = vector<ll>;using vs = vector<string>;using vb = vector<bool>;
using vpii = vector<pii>;using vpli = vector<pli>;using vpll = vector<pll>;using vpil = vector<pil>;
using vvi = vector<vector<int>>;using vvl = vector<vector<ll>>;using vvs = vector<vector<string>>;using vvb = vector<vector<bool>>;
using vvpii = vector<vector<pii>>;using vvpli = vector<vector<pli>>;using vvpll = vector<vpll>;using vvpil = vector<vpil>;
using mint = modint998244353;
//using mint = modint1000000007;
//using mint = dynamic_modint<0>;
using vm = vector<mint>;
using vvm = vector<vector<mint>>;
vector<int> dx={1,0,-1,0,1,1,-1,-1},dy={0,1,0,-1,1,-1,1,-1};
ll gcd(ll a, ll b) { return a?gcd(b%a,a):b;}
ll lcm(ll a, ll b) { return a/gcd(a,b)*b;}
#define yes {cout <<"Yes"<<endl;}
#define no {cout <<"No"<<endl;}
const double eps = 1e-10;
const ll LINF = 1001002003004005006ll;
const int INF = 1001001001;
#ifdef MY_LOCAL_DEBUG
#define show(x) cerr<<#x<<" = "<<x<<endl
#define showp(p) cerr<<#p<<" = "<<p.fi<<" : "<<p.se<<endl
#define show2(x,y) cerr<<#x<<" = "<<x<<" : "<<#y<<" = "<<y<<endl
#define show3(x,y,z) cerr<<#x<<" = "<<x<<" : "<<#y<<" = "<<y<<" : "<<#z<<" = "<<z<<endl
#define show4(x,y,z,x2) cerr<<#x<<" = "<<x<<" : "<<#y<<" = "<<y<<" : "<<#z<<" = "<<z<<" : "<<#x2<<" = "<<x2<<endl
#define test(x) cout << "test" << x << endl
#define showv(v) {fore(vy , v) {cout << vy << " ";} cout << endl;}
#define showv2(v) fore(vy , v) cout << vy << "\n";
#define showvm(v) {fore(vy , v) {cout << vy.val() << " ";} cout << endl;}
#define showvm2(v) fore(vy , v) cout << vy.val() << "\n";
#else
#define show(x)
#define showp(p)
#define show2(x,y)
#define show3(x,y,z)
#define show4(x,y,z,x2)
#define test(x)
#define showv(v)
#define showv2(v)
#define showvm(v)
#define showvm2(v)
#endif

struct combination {
  vector<mint> fact, ifact;
  combination(int n):fact(n+1),ifact(n+1) {
    fact[0] = 1;
    for (int i = 1; i <= n; ++i) fact[i] = fact[i-1]*i;
    ifact[n] = fact[n].inv();
    for (int i = n; i >= 1; --i) ifact[i-1] = ifact[i]*i;
  }
  mint operator()(int n, int k) {
    if (k < 0 || k > n) return 0;
    return fact[n]*ifact[k]*ifact[n-k];
  }
} com(10000005);

namespace math{
    vvi div,mul;
    void div_init(int n){
        div.resize(n+1);
        mul.resize(n+1);
        for(int i = 1;i <= n;i++){
            for(int j = i;j <= n;j+=i){
                div[j].pb(i);
                mul[i].pb(j);
            }
        }
        return;
    }

    vl divisor(ll x){
        vl res;
        for(ll i=1;i*i<=x;i++){
            if (x%i != 0) continue;
            res.pb(i);
            if (i*i != x) res.pb(x/i); 
        }
        sort(rng(res));
        return res;
    }
    ll floorsqrt(ll x) {
        ll l = 0, r = ll(2e9)+1;
        while (l+1<r) {
          ll c = (l+r)/2;
          if (c*c <= x) l = c; else r = c;
        }
        return l;
    }
    ll floorlog(int a,ll x){
        ll tmp=1; ll ret=0;
        while(tmp <= x){
            if (tmp >= LLONG_MAX/a) break;
            tmp *= a;
            ret++;
        }
        ret--;
        return ret;
    }
    ll pow(ll x , int a){
        assert(x > 0);
        assert(a >= 0);
        ll ret = 1;
        rep(_,a){
            assert (ret < LLONG_MAX/x);
            ret *= x;
        }
        return ret;
    }
    ll base(ll x,int a){
        ll ans=0,y;
        for (ll i=0;x>0;i++){
            y = x/a;
            ans += (x - y*a)*pow(10,i);
            x = y;
        }
        return ans;
    }
    string baseS(ll x,int a){
        string ans;
        ll y;
        for (ll i=0;x>0;i++){
            y = x/a;
            ans += '0' + (x - y*a);
            x = y;
        }
        reverse(rng(ans));
        return ans;
    }
    template<typename T>
    ll inv(vector<T>& v){
        int n = sz(v);
        map<T,int> mp;
        fore(y,v) mp[y] = 0;
        int m = 0;
        fore(y,mp) y.se = m++;
        fenwick_tree<T> fw(m);
        ll ret = 0;
        rep(i,n){
            int k = mp[v[i]];
            ret += fw.sum(k+1,m);
            fw.add(k,1);
        }
        return ret;
    }
}

// namespace math

// .div.mul : div[i]、mul[i]はそれぞれiの約数、倍数を格納している。
// .div_init(n) : div,mulを初期化。引数はnまで。n < 3e5程
// .divisor(x) : xの約数列挙。xは64bit整数。
// .floorsqrt(x) : floor(sqrt(x))。xは64bit整数。誤差は発生しない。
// .floorlog(a , x) : floor(loga(x))。xは64bit整数。誤差は発生しない。
// .pow(x , a) : x^a。誤差は発生しない。
// .base(x , a) : x(10進数)をa進数表記に。1 <= a <= 10。戻り値はll型。 
// .baseS(x , a) : x(10進数)をa進数表記に。1 <= a <= 10。戻り値はstring型。 
// .inv(v) : vの転倒数。

void solve(){
    ll n,m; cin>>n>>m;

    auto f = [&](ll x,ll y)->mint{
        if (x%2 != y%2) return 0;
        ll a = (x+y)/2;
        ll b = (x-y)/2;
        if (b<0) return 0;
        ll c = n-a-b;
        if (c<0 || c%2==1) return 0;
        c /= 2;
        ll d = (n-c);
        mint tmp = com(n,c) * com(n,d-a);
        if (a!=0) tmp *= 2;
        if (b!=0) tmp *= 2;
        return tmp;
    };
    if (m < 0) m *= -1;
    mint ans = 0;
    if (m>0){
        vl d = math::divisor(m);
        fore(y , d){
            ll x = m/y;
            ans += f(x,y);
        }
    }else{
        rep(i,n+1){
            mint tmp = f(i,0);
            // cout << tmp.val() << endl;
            ans += tmp;
        }
        // outm;
    }
    ans /= mint(4).pow(n);
    outm;

    return;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);

    int t = 1;
    //cin>>t;

    rep(i,t){
        solve();
    }

    return 0;
}