/**
 *    author:  tourist
 *    created: 14.07.2019 17:15:45       
**/
#undef _GLIBCXX_DEBUG

#include <bits/stdc++.h>

using namespace std;

template <typename A, typename B>
string to_string(pair<A, B> p);

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p);

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p);

string to_string(const string& s) {
  return '"' + s + '"';
}

string to_string(const char* s) {
  return to_string((string) s);
}

string to_string(bool b) {
  return (b ? "true" : "false");
}

string to_string(vector<bool> v) {
  bool first = true;
  string res = "{";
  for (int i = 0; i < static_cast<int>(v.size()); i++) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(v[i]);
  }
  res += "}";
  return res;
}

template <size_t N>
string to_string(bitset<N> v) {
  string res = "";
  for (size_t i = 0; i < N; i++) {
    res += static_cast<char>('0' + v[i]);
  }
  return res;
}

template <typename A>
string to_string(A v) {
  bool first = true;
  string res = "{";
  for (const auto &x : v) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(x);
  }
  res += "}";
  return res;
}

template <typename A, typename B>
string to_string(pair<A, B> p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " + to_string(get<2>(p)) + ")";
}

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " + to_string(get<2>(p)) + ", " + to_string(get<3>(p)) + ")";
}

void debug_out() { cerr << endl; }

template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
  cerr << " " << to_string(H);
  debug_out(T...);
}

#ifdef LOCAL
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif

template <typename T>
T inverse(T a, T m) {
  T u = 0, v = 1;
  while (a != 0) {
    T t = m / a;
    m -= t * a; swap(a, m);
    u -= t * v; swap(u, v);
  }
  assert(m == 1);
  return u;
}

template <typename T>
class Modular {
 public:
  using Type = typename decay<decltype(T::value)>::type;

  constexpr Modular() : value() {}
  template <typename U>
  Modular(const U& x) {
    value = normalize(x);
  }

  template <typename U>
  static Type normalize(const U& x) {
    Type v;
    if (-mod() <= x && x < mod()) v = static_cast<Type>(x);
    else v = static_cast<Type>(x % mod());
    if (v < 0) v += mod();
    return v;
  }

  const Type& operator()() const { return value; }
  template <typename U>
  explicit operator U() const { return static_cast<U>(value); }
  constexpr static Type mod() { return T::value; }

  Modular& operator+=(const Modular& other) { if ((value += other.value) >= mod()) value -= mod(); return *this; }
  Modular& operator-=(const Modular& other) { if ((value -= other.value) < 0) value += mod(); return *this; }
  template <typename U> Modular& operator+=(const U& other) { return *this += Modular(other); }
  template <typename U> Modular& operator-=(const U& other) { return *this -= Modular(other); }
  Modular& operator++() { return *this += 1; }
  Modular& operator--() { return *this -= 1; }
  Modular operator++(int) { Modular result(*this); *this += 1; return result; }
  Modular operator--(int) { Modular result(*this); *this -= 1; return result; }
  Modular operator-() const { return Modular(-value); }

  template <typename U = T>
  typename enable_if<is_same<typename Modular<U>::Type, int>::value, Modular>::type& operator*=(const Modular& rhs) {
#ifdef _WIN32
    uint64_t x = static_cast<int64_t>(value) * static_cast<int64_t>(rhs.value);
    uint32_t xh = static_cast<uint32_t>(x >> 32), xl = static_cast<uint32_t>(x), d, m;
    asm(
      "divl %4; \n\t"
      : "=a" (d), "=d" (m)
      : "d" (xh), "a" (xl), "r" (mod())
    );
    value = m;
#else
    value = normalize(static_cast<int64_t>(value) * static_cast<int64_t>(rhs.value));
#endif
    return *this;
  }
  template <typename U = T>
  typename enable_if<is_same<typename Modular<U>::Type, int64_t>::value, Modular>::type& operator*=(const Modular& rhs) {
    int64_t q = static_cast<int64_t>(static_cast<long double>(value) * rhs.value / mod());
    value = normalize(value * rhs.value - q * mod());
    return *this;
  }
  template <typename U = T>
  typename enable_if<!is_integral<typename Modular<U>::Type>::value, Modular>::type& operator*=(const Modular& rhs) {
    value = normalize(value * rhs.value);
    return *this;
  }

  Modular& operator/=(const Modular& other) { return *this *= Modular(inverse(other.value, mod())); }

  template <typename U>
  friend const Modular<U>& abs(const Modular<U>& v) { return v; }

  template <typename U>
  friend bool operator==(const Modular<U>& lhs, const Modular<U>& rhs);

  template <typename U>
  friend bool operator<(const Modular<U>& lhs, const Modular<U>& rhs);

  template <typename U>
  friend std::istream& operator>>(std::istream& stream, Modular<U>& number);

 private:
  Type value;
};

template <typename T> bool operator==(const Modular<T>& lhs, const Modular<T>& rhs) { return lhs.value == rhs.value; }
template <typename T, typename U> bool operator==(const Modular<T>& lhs, U rhs) { return lhs == Modular<T>(rhs); }
template <typename T, typename U> bool operator==(U lhs, const Modular<T>& rhs) { return Modular<T>(lhs) == rhs; }

template <typename T> bool operator!=(const Modular<T>& lhs, const Modular<T>& rhs) { return !(lhs == rhs); }
template <typename T, typename U> bool operator!=(const Modular<T>& lhs, U rhs) { return !(lhs == rhs); }
template <typename T, typename U> bool operator!=(U lhs, const Modular<T>& rhs) { return !(lhs == rhs); }

template <typename T> bool operator<(const Modular<T>& lhs, const Modular<T>& rhs) { return lhs.value < rhs.value; }

template <typename T> Modular<T> operator+(const Modular<T>& lhs, const Modular<T>& rhs) { return Modular<T>(lhs) += rhs; }
template <typename T, typename U> Modular<T> operator+(const Modular<T>& lhs, U rhs) { return Modular<T>(lhs) += rhs; }
template <typename T, typename U> Modular<T> operator+(U lhs, const Modular<T>& rhs) { return Modular<T>(lhs) += rhs; }

template <typename T> Modular<T> operator-(const Modular<T>& lhs, const Modular<T>& rhs) { return Modular<T>(lhs) -= rhs; }
template <typename T, typename U> Modular<T> operator-(const Modular<T>& lhs, U rhs) { return Modular<T>(lhs) -= rhs; }
template <typename T, typename U> Modular<T> operator-(U lhs, const Modular<T>& rhs) { return Modular<T>(lhs) -= rhs; }

template <typename T> Modular<T> operator*(const Modular<T>& lhs, const Modular<T>& rhs) { return Modular<T>(lhs) *= rhs; }
template <typename T, typename U> Modular<T> operator*(const Modular<T>& lhs, U rhs) { return Modular<T>(lhs) *= rhs; }
template <typename T, typename U> Modular<T> operator*(U lhs, const Modular<T>& rhs) { return Modular<T>(lhs) *= rhs; }

template <typename T> Modular<T> operator/(const Modular<T>& lhs, const Modular<T>& rhs) { return Modular<T>(lhs) /= rhs; }
template <typename T, typename U> Modular<T> operator/(const Modular<T>& lhs, U rhs) { return Modular<T>(lhs) /= rhs; }
template <typename T, typename U> Modular<T> operator/(U lhs, const Modular<T>& rhs) { return Modular<T>(lhs) /= rhs; }

template<typename T, typename U>
Modular<T> power(const Modular<T>& a, const U& b) {
  assert(b >= 0);
  Modular<T> x = a, res = 1;
  U p = b;
  while (p > 0) {
    if (p & 1) res *= x;
    x *= x;
    p >>= 1;
  }
  return res;
}

template <typename T>
bool IsZero(const Modular<T>& number) {
  return number() == 0;
}

template <typename T>
string to_string(const Modular<T>& number) {
  return to_string(number());
}

template <typename T>
std::ostream& operator<<(std::ostream& stream, const Modular<T>& number) {
  return stream << number();
}

template <typename T>
std::istream& operator>>(std::istream& stream, Modular<T>& number) {
  typename common_type<typename Modular<T>::Type, int64_t>::type x;
  stream >> x;
  number.value = Modular<T>::normalize(x);
  return stream;
}

/*
using ModType = int;

struct VarMod { static ModType value; };
ModType VarMod::value;
ModType& md = VarMod::value;
using Mint = Modular<VarMod>;
*/

constexpr int md = 998244353;
using Mint = Modular<std::integral_constant<decay<decltype(md)>::type, md>>;

vector<Mint> fact;
vector<Mint> inv_fact;

template <typename T>
class NTT {
 public:
  using Type = typename decay<decltype(T::value)>::type;

  static Type md;
  static Modular<T> root;
  static int base;
  static int max_base;
  static vector<Modular<T>> roots;
  static vector<int> rev;

  static void clear() {
    root = 0;
    base = 0;
    max_base = 0;
    roots.clear();
    rev.clear();
  }

  static void init() {
    md = T::value;
    assert(md >= 3 && md % 2 == 1);
    auto tmp = md - 1;
    max_base = 0;
    while (tmp % 2 == 0) {
      tmp /= 2;
      max_base++;
    }
    root = 2;
    while (power(root, (md - 1) >> 1) == 1) {
      root++;
    }
    assert(power(root, md - 1) == 1);
    root = power(root, (md - 1) >> max_base);
    base = 1;
    rev = {0, 1};
    roots = {0, 1};
  }

  static void ensure_base(int nbase) {
    if (md != T::value) {
      clear();
    }
    if (roots.empty()) {
      init();
    }
    if (nbase <= base) {
      return;
    }
    assert(nbase <= max_base);
    rev.resize(1 << nbase);
    for (int i = 0; i < (1 << nbase); i++) {
      rev[i] = (rev[i >> 1] >> 1) + ((i & 1) << (nbase - 1));
    }
    roots.resize(1 << nbase);
    while (base < nbase) {
      Modular<T> z = power(root, 1 << (max_base - 1 - base));
      for (int i = 1 << (base - 1); i < (1 << base); i++) {
        roots[i << 1] = roots[i];
        roots[(i << 1) + 1] = roots[i] * z;
      }
      base++;
    }
  }

  static void fft(vector<Modular<T>> &a) {
    int n = (int) a.size();
    assert((n & (n - 1)) == 0);
    int zeros = __builtin_ctz(n);
    ensure_base(zeros);
    int shift = base - zeros;
    for (int i = 0; i < n; i++) {
      if (i < (rev[i] >> shift)) {
        swap(a[i], a[rev[i] >> shift]);
      }
    }
    for (int k = 1; k < n; k <<= 1) {
      for (int i = 0; i < n; i += 2 * k) {
        for (int j = 0; j < k; j++) {
          Modular<T> x = a[i + j];
          Modular<T> y = a[i + j + k] * roots[j + k];
          a[i + j] = x + y;
          a[i + j + k] = x - y;
        }
      }
    }
  }

  static vector<Modular<T>> multiply(vector<Modular<T>> a, vector<Modular<T>> b) {
    if (a.empty() || b.empty()) {
      return {};
    }
    int eq = (a == b);
    int need = (int) a.size() + (int) b.size() - 1;
    int nbase = 0;
    while ((1 << nbase) < need) nbase++;
    ensure_base(nbase);
    int sz = 1 << nbase;
    a.resize(sz);
    b.resize(sz);
    fft(a);
    if (eq) b = a; else fft(b);
    Modular<T> inv_sz = 1 / static_cast<Modular<T>>(sz);
    for (int i = 0; i < sz; i++) {
      a[i] *= b[i] * inv_sz;
    }
    reverse(a.begin() + 1, a.end());
    fft(a);
    a.resize(need);
    return a;
  }
};

template <typename T> typename NTT<T>::Type NTT<T>::md;
template <typename T> Modular<T> NTT<T>::root;
template <typename T> int NTT<T>::base;
template <typename T> int NTT<T>::max_base;
template <typename T> vector<Modular<T>> NTT<T>::roots;
template <typename T> vector<int> NTT<T>::rev;

template <typename T>
vector<Modular<T>> inverse(const vector<Modular<T>>& a) {
  assert(!a.empty());
  int n = (int) a.size();
  vector<Modular<T>> b = {1 / a[0]};
  while ((int) b.size() < n) {
    vector<Modular<T>> x(a.begin(), a.begin() + min(a.size(), b.size() << 1));
    x.resize(b.size() << 1);
    b.resize(b.size() << 1);
    vector<Modular<T>> c = b;
    NTT<T>::fft(c);
    NTT<T>::fft(x);
    Modular<T> inv = 1 / static_cast<Modular<T>>((int) x.size());
    for (int i = 0; i < (int) x.size(); i++) {
      x[i] *= c[i] * inv;
    }
    reverse(x.begin() + 1, x.end());
    NTT<T>::fft(x);
    rotate(x.begin(), x.begin() + (x.size() >> 1), x.end());
    fill(x.begin() + (x.size() >> 1), x.end(), 0);
    NTT<T>::fft(x);
    for (int i = 0; i < (int) x.size(); i++) {
      x[i] *= c[i] * inv;
    }
    reverse(x.begin() + 1, x.end());
    NTT<T>::fft(x);
    for (int i = 0; i < ((int) x.size() >> 1); i++) {
      b[i + ((int) x.size() >> 1)] = -x[i];
    }
  }
  b.resize(n);
  return b;
}

template <typename T>
vector<Modular<T>> inverse_old(vector<Modular<T>> a) {
  assert(!a.empty());
  int n = (int) a.size();
  if (n == 1) {
    return {1 / a[0]};
  }
  int m = (n + 1) >> 1;
  vector<Modular<T>> b = inverse(vector<Modular<T>>(a.begin(), a.begin() + m));
  int need = n << 1;
  int nbase = 0;
  while ((1 << nbase) < need) {
    ++nbase;
  }
  NTT<T>::ensure_base(nbase);
  int size = 1 << nbase;
  a.resize(size);
  b.resize(size);
  NTT<T>::fft(a);
  NTT<T>::fft(b);
  Modular<T> inv = 1 / static_cast<Modular<T>>(size);
  for (int i = 0; i < size; ++i) {
    a[i] = (2 - a[i] * b[i]) * b[i] * inv;
  }
  reverse(a.begin() + 1, a.end());
  NTT<T>::fft(a);
  a.resize(n);
  return a;
}

template <typename T>
vector<Modular<T>> operator*(const vector<Modular<T>>& a, const vector<Modular<T>>& b) {
  if (a.empty() || b.empty()) {
    return {};
  }
  if (min(a.size(), b.size()) < 150) {
    vector<Modular<T>> c(a.size() + b.size() - 1, 0);
    for (int i = 0; i < (int) a.size(); i++) {
      for (int j = 0; j < (int) b.size(); j++) {
        c[i + j] += a[i] * b[j];
      }
    }
    return c;
  }
  return NTT<T>::multiply(a, b);
}

template <typename T>
vector<Modular<T>>& operator*=(vector<Modular<T>>& a, const vector<Modular<T>>& b) {
  return a = a * b;
}

template <typename T>
vector<T>& operator+=(vector<T>& a, const vector<T>& b) {
  if (a.size() < b.size()) {
    a.resize(b.size());
  }
  for (int i = 0; i < (int) b.size(); i++) {
    a[i] += b[i];
  }
  return a;
}

template <typename T>
vector<T> operator+(const vector<T>& a, const vector<T>& b) {
  vector<T> c = a;
  return c += b;
}

template <typename T>
vector<T>& operator-=(vector<T>& a, const vector<T>& b) {
  if (a.size() < b.size()) {
    a.resize(b.size());
  }
  for (int i = 0; i < (int) b.size(); i++) {
    a[i] -= b[i];
  }
  return a;
}

template <typename T>
vector<T> operator-(const vector<T>& a, const vector<T>& b) {
  vector<T> c = a;
  return c -= b;
}

template <typename T>
vector<T> operator-(const vector<T>& a) {
  vector<T> c = a;
  for (int i = 0; i < (int) c.size(); i++) {
    c[i] = -c[i];
  }
  return c;
}

template <typename T>
vector<T> operator*(const vector<T>& a, const vector<T>& b) {
  if (a.empty() || b.empty()) {
    return {};
  }
  vector<T> c(a.size() + b.size() - 1, 0);
  for (int i = 0; i < (int) a.size(); i++) {
    for (int j = 0; j < (int) b.size(); j++) {
      c[i + j] += a[i] * b[j];
    }
  }
  return c;
}

template <typename T>
vector<T>& operator*=(vector<T>& a, const vector<T>& b) {
  return a = a * b;
}

template <typename T>
vector<T> inverse(const vector<T>& a) {
  assert(!a.empty());
  int n = (int) a.size();
  vector<T> b = {1 / a[0]};
  while ((int) b.size() < n) {
    vector<T> a_cut(a.begin(), a.begin() + min(a.size(), b.size() << 1));
    vector<T> x = b * b * a_cut;
    b.resize(b.size() << 1);
    for (int i = (int) b.size() >> 1; i < (int) min(x.size(), b.size()); i++) {
      b[i] = -x[i];
    }
  }
  b.resize(n);
  return b;
}

template <typename T>
vector<T>& operator/=(vector<T>& a, const vector<T>& b) {
  int n = (int) a.size();
  int m = (int) b.size();
  if (n < m) {
    a.clear();
  } else {
    vector<T> d = b;
    reverse(a.begin(), a.end());
    reverse(d.begin(), d.end());
    d.resize(n - m + 1);
    a *= inverse(d);
    a.erase(a.begin() + n - m + 1, a.end());
    reverse(a.begin(), a.end());
  }
  return a;
}

template <typename T>
vector<T> operator/(const vector<T>& a, const vector<T>& b) {
  vector<T> c = a;
  return c /= b;
}

template <typename T>
vector<T>& operator%=(vector<T>& a, const vector<T>& b) {
  int n = (int) a.size();
  int m = (int) b.size();
  if (n >= m) {
    vector<T> c = (a / b) * b;
    a.resize(m - 1);
    for (int i = 0; i < m - 1; i++) {
      a[i] -= c[i];
    }
  }
  return a;
}

template <typename T>
vector<T> operator%(const vector<T>& a, const vector<T>& b) {
  vector<T> c = a;
  return c %= b;
}

template <typename T, typename U>
vector<T> power(const vector<T>& a, const U& b, const vector<T>& c) {
  assert(b >= 0);
  vector<U> binary;
  U bb = b;
  while (bb > 0) {
    binary.push_back(bb & 1);
    bb >>= 1;
  }
  vector<T> res = vector<T>{1} % c;
  for (int j = (int) binary.size() - 1; j >= 0; j--) {
    res = res * res % c;
    if (binary[j] == 1) {
      res = res * a % c;
    }
  }
  return res;
}

template <typename T>
vector<T> derivative(const vector<T>& a) {
  vector<T> c = a;
  for (int i = 0; i < (int) c.size(); i++) {
    c[i] *= i;   	
  }
  if (!c.empty()) {
    c.erase(c.begin());
  }
  return c;
}
 
template <typename T>
vector<T> primitive(const vector<T>& a) {
  vector<T> c = a;
  c.insert(c.begin(), 0);
  for (int i = 1; i < (int) c.size(); i++) {
    c[i] /= i;
  }
  return c;
}

template <typename T>
vector<T> logarithm(const vector<T>& a) {
  assert(!a.empty() && a[0] == 1);
  vector<T> u = primitive(derivative(a) * inverse(a));
  u.resize(a.size());
  return u;
}
 
template <typename T>
vector<T> exponent(const vector<T>& a) {
  assert(!a.empty() && a[0] == 0);
  int n = (int) a.size();
  vector<T> b = {1};
  while ((int) b.size() < n) {
    vector<T> x(a.begin(), a.begin() + min(a.size(), b.size() << 1));
    x[0] += 1;
    vector<T> old_b = b;
    b.resize(b.size() << 1);
    x -= logarithm(b);
    x *= old_b;
    for (int i = (int) b.size() >> 1; i < (int) min(x.size(), b.size()); i++) {
      b[i] = x[i];
    }
  }
  b.resize(n);
  return b;
}

template <typename T>
vector<T> multiply(const vector<vector<T>>& a) {
  if (a.empty()) {
    return {0};
  }
  function<vector<T>(int, int)> mult = [&](int l, int r) {
    if (l == r) {
      return a[l];
    }
    int y = (l + r) >> 1;
    return mult(l, y) * mult(y + 1, r);
  };
  return mult(0, (int) a.size() - 1);
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, m;
  cin >> n >> m;
  fact.resize(n + 1);
  inv_fact.resize(n + 1);
  fact[0] = 1;
  for (int i = 1; i <= n; i++) {
    fact[i] = fact[i - 1] * i;
  }
  inv_fact[n] = 1 / fact[n];
  for (int i = n - 1; i >= 0; i--) {
    inv_fact[i] = inv_fact[i + 1] * (i + 1);
  }
  vector<Mint> poly(n + 1);
  Mint invm1 = 1 / Mint(n + 1);
  for (int i = 0; i <= n; i++) {
    poly[i] = (n + 1 - i) * inv_fact[i] * invm1;
  }
  vector<Mint> z = exponent(logarithm(poly) * vector<Mint>{m});
  Mint ans = 0;
  for (int i = 0; i <= n; i++) {
    ans += z[i] * inv_fact[n - i];
  }
  ans *= power(Mint(n + 1), m);
  ans *= fact[n];
  cout << ans << '\n';
  return 0;
}


Measured memory_bytes: 48756