#include namespace { #pragma GCC diagnostic ignored "-Wunused-function" #include #pragma GCC diagnostic warning "-Wunused-function" using namespace std; using namespace atcoder; #define rep(i,n) for(int i = 0; i < (int)(n); i++) #define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; i--) #define all(x) begin(x), end(x) #define rall(x) rbegin(x), rend(x) template bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; } template bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; } using ll = long long; using P = pair; using VI = vector; using VVI = vector; using VL = vector; using VVL = vector; using mint = modint998244353; constexpr int FACT_SIZE = 1500000; mint Fact[FACT_SIZE + 1]; mint iFact[FACT_SIZE + 1]; const auto fact_init = [] { Fact[0] = mint::raw(1); for(int i = 1; i <= FACT_SIZE; ++i) { Fact[i] = Fact[i-1] * i; } iFact[FACT_SIZE] = Fact[FACT_SIZE].inv(); for(int i = FACT_SIZE; i; --i) { iFact[i-1] = iFact[i] * i; } return false; }(); mint comb(int n, int k) { if (k == 0) return mint::raw(1); assert(n >= 0 && k >= 0); if (k > n) return mint::raw(0); return Fact[n] * iFact[n - k] * iFact[k]; } mint icomb(int n, int k) { return iFact[n] * Fact[n - k] * Fact[k]; } mint fact(int n) {return Fact[n];} mint perm(int n, int k) { assert(0 <= n); return Fact[n] * iFact[n - k]; } template vector divisors(T x) { vector res1, res2; T d = 1; for(; d * d < x; d++) { if (x % d == 0) { res1.emplace_back(d); res2.emplace_back(x / d); } } if (d * d == x) res1.emplace_back(d); res1.insert(res1.end(), res2.rbegin(), res2.rend()); return res1; } } int main() { ios::sync_with_stdio(false); cin.tie(0); ll n, m; cin >> n >> m; // m *= 4; m = abs(m); mint ans; auto f = [&](ll c) { ll x = n + c; if (x % 2) return mint(); x /= 2; if (0 <= x && x <= n) return comb(n, x); else return mint(); }; if (m == 0) { mint v = f(0); ans = 2 * v * mint(2).pow(n) - v * v; } else { for(ll x: divisors(m)) { ll y = m / x; // cout << x << ' ' << y << ' ' << f(x).val() << ' ' << f(y).val() << endl; ans += f(x) * f(y); } ans *= 2; } ans /= mint(4).pow(n); cout << ans.val() << endl; }