// Code by Heratino & Nelofus
// Narcissus & どうか安寧な記憶を

#include <bits/stdc++.h>
using i64 = long long;

template<class T>
constexpr T fpow(T a, i64 b) {
	T res {1};
	for (; b; b /= 2, a *= a) {
		if (b % 2) {
			res *= a;
		}
	}
	return res;
}

constexpr i64 mul(i64 a, i64 b, i64 p) {
	i64 res = a * b - i64(1.L * a * b / p) * p;
	res %= p;
	if (res < 0) {
		res += p;
	}
	return res;
}

template<i64 P>
struct MInt {
	i64 x;
	constexpr MInt() : x {0} {}
	constexpr MInt(i64 x) : x {norm(x % getMod())} {}

	static i64 Mod;
	constexpr static i64 getMod() {
		if (P > 0) {
			return P;
		} else {
			return Mod;
		}
	}
	constexpr static void setMod(i64 Mod_) {
		Mod = Mod_;
	}
	constexpr i64 norm(i64 x) const {
		if (x < 0) {
			x += getMod();
		}
		if (x >= getMod()) {
			x -= getMod();
		}
		return x;
	}
	constexpr i64 val() const {
		return x;
	}
	constexpr MInt operator-() const {
		MInt res;
		res.x = norm(getMod() - x);
		return res;
	}
	constexpr MInt inv() const {
		return fpow(*this, getMod() - 2);
	}
	constexpr MInt &operator*=(MInt rhs) & {
		if (getMod() < (1ULL << 31)) {
			x = x * rhs.x % int(getMod());
		} else {
			x = mul(x, rhs.x, getMod());
		}
		return *this;
	}
	constexpr MInt &operator+=(MInt rhs) & {
		x = norm(x + rhs.x);
		return *this;
	}
	constexpr MInt &operator-=(MInt rhs) & {
		x = norm(x - rhs.x);
		return *this;
	}
	constexpr MInt &operator/=(MInt rhs) & {
		return *this *= rhs.inv();
	}
	friend constexpr MInt operator*(MInt lhs, MInt rhs) {
		MInt res = lhs;
		res *= rhs;
		return res;
	}
	friend constexpr MInt operator+(MInt lhs, MInt rhs) {
		MInt res = lhs;
		res += rhs;
		return res;
	}
	friend constexpr MInt operator-(MInt lhs, MInt rhs) {
		MInt res = lhs;
		res -= rhs;
		return res;
	}
	friend constexpr MInt operator/(MInt lhs, MInt rhs) {
		MInt res = lhs;
		res /= rhs;
		return res;
	}
	friend constexpr std::istream &operator>>(std::istream &is, MInt &a) {
		i64 v;
		is >> v;
		a = MInt(v);
		return is;
	}
	friend constexpr std::ostream &operator<<(std::ostream &os, const MInt &a) {
		return os << a.val();
	}
	friend constexpr bool operator==(MInt lhs, MInt rhs) {
		return lhs.val() == rhs.val();
	}
	friend constexpr bool operator!=(MInt lhs, MInt rhs) {
		return lhs.val() != rhs.val();
	}
	friend constexpr bool operator<(MInt lhs, MInt rhs) {
		return lhs.val() < rhs.val();
	}
};

template<>
i64 MInt<0>::Mod = 998244353;
constexpr int P = 998244353;
using Z = MInt<P>;

struct Comb {
	int n;
	std::vector<Z> _fac;
	std::vector<Z> _invfac;
	std::vector<Z> _inv;

	Comb() : n{0}, _fac{1}, _invfac{1}, _inv{0} {}
	Comb(int n) : Comb() {
		init(n);
	}

	void init(int m) {
		m = std::min(0ll + m, Z::getMod() - 1);
		if (m <= n) return;
		_fac.resize(m + 1);
		_invfac.resize(m + 1);
		_inv.resize(m + 1);

		for (int i = n + 1; i <= m; i++) {
			_fac[i] = _fac[i - 1] * i;
		}
		_invfac[m] = _fac[m].inv();
		for (int i = m; i > n; i--) {
			_invfac[i - 1] = _invfac[i] * i;
			_inv[i] = _invfac[i] * _fac[i - 1];
		}
		n = m;
	}

	Z fac(int m) {
		if (m > n) init(2 * m);
		return _fac[m];
	}
	Z invfac(int m) {
		if (m > n) init(2 * m);
		return _invfac[m];
	}
	Z inv(int m) {
		if (m > n) init(2 * m);
		return _inv[m];
	}
	Z binom(int n, int m) {
		if (n < m || m < 0) return 0;
		return fac(n) * invfac(m) * invfac(n - m);
	}
} comb;

constexpr int N = 110;
int n, m;
// 斯特林数
Z S[N][N];
Z f[N][N];
Z g[N][N];

int main() {
	std::cin >> n >> m;

	S[0][0] = 1;
	g[0][0] = 1;

	for (int i = 1; i < N; i++)
		for (int j = 1; j <= i; j++) {
			S[i][j] = j * S[i - 1][j] + S[i - 1][j - 1];
			g[i][j] = S[i][j] * comb.fac(j);
		}

	auto multiBinom = [&](int x, int y, int z) -> Z {
		return comb.fac(x + y + z) * comb.invfac(x) * comb.invfac(y) * comb.invfac(z);
	};
	for (int x = 1; x <= n; x++) {
		for (int y = 1; y <= n; y++) {
			for (int k = 1; k <= y; k++) {
				for (int c = 1; c <= x; c++) {
					Z fac = c * comb.inv(x);
					Z res = 0;
					for (int l1 = 0 + (k - 1); l1 <= x - c; l1++) {
						if (l1 && !(k - 1))
							break;
						int l2 = x - c - l1;
						if (l2 < y - k)
							break;
						if (l2 && !(y - k))
							continue;
						Z part1 = multiBinom(l1, c, l2);
						Z part2 = g[l1][k - 1] * f[l2][y - k] + g[l2][y - k] * f[l1][k - 1] + g[l1][k - 1] * g[l2][y - k] * x;
						res += part1 * part2;
					}
					f[x][y] += fac * res;
				}
			}
		}
	}
	Z ans = 0;
	Z C = 1;
	for (int i = 1; i <= n; i++) {
		C *= (m - i + 1) * comb.inv(i);
		ans += C * f[n][i];
	}
	std::cout << ans << '\n';
	return 0;
}