#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <chrono>
#include <cmath>
#include <complex>
#include <cstdint>
#include <cstring>
#include <ctime>
#include <deque>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <unordered_map>
#include <unordered_set>

template <int mod>
struct ModInt {
  int x;
  ModInt() : x(0) {}
  ModInt(long long y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {}
  ModInt& operator+=(const ModInt& p) {
    if ((x += p.x) >= mod) x -= mod;
    return *this;
  }
  ModInt& operator-=(const ModInt& p) {
    if ((x += mod - p.x) >= mod) x -= mod;
    return *this;
  }
  ModInt& operator*=(const ModInt& p) {
    x = (int)(1LL * x * p.x % mod);
    return *this;
  }
  ModInt& operator/=(const ModInt& p) {
    *this *= p.inverse();
    return *this;
  }
  ModInt& operator^=(long long p) {  // quick_pow here:3
    ModInt res = 1;
    for (; p; p >>= 1) {
      if (p & 1) res *= *this;
      *this *= *this;
    }
    return *this = res;
  }
  ModInt operator-() const { return ModInt(-x); }
  ModInt operator+(const ModInt& p) const { return ModInt(*this) += p; }
  ModInt operator-(const ModInt& p) const { return ModInt(*this) -= p; }
  ModInt operator*(const ModInt& p) const { return ModInt(*this) *= p; }
  ModInt operator/(const ModInt& p) const { return ModInt(*this) /= p; }
  ModInt operator^(long long p) const { return ModInt(*this) ^= p; }
  bool operator==(const ModInt& p) const { return x == p.x; }
  bool operator!=(const ModInt& p) const { return x != p.x; }
  explicit operator int() const { return x; }  // added by QCFium
  ModInt operator=(const int p) {
    x = p;
    return ModInt(*this);
  }  // added by QCFium
  ModInt inverse() const {
    int a = x, b = mod, u = 1, v = 0, t;
    while (b > 0) {
      t = a / b;
      a -= t * b;
      std::swap(a, b);
      u -= t * v;
      std::swap(u, v);
    }
    return ModInt(u);
  }
  friend std::ostream& operator<<(std::ostream& os, const ModInt<mod>& p) {
    return os << p.x;
  }
  friend std::istream& operator>>(std::istream& is, ModInt<mod>& a) {
    long long x;
    is >> x;
    a = ModInt<mod>(x);
    return (is);
  }
};

using mint = ModInt<998244353>;
// const int MOD = 1000000007;
const int MOD = 998244353;
struct MComb {
  std::vector<mint> fact;
  std::vector<mint> inversed;
  MComb(int n) {  // O(n+log(mod))
    fact = std::vector<mint>(n + 1, 1);
    for (int i = 1; i <= n; i++) fact[i] = fact[i - 1] * mint(i);
    inversed = std::vector<mint>(n + 1);
    inversed[n] = fact[n] ^ (MOD - 2);
    for (int i = n - 1; i >= 0; i--)
      inversed[i] = inversed[i + 1] * mint(i + 1);
  }
  mint ncr(int n, int r) {
    if (n < r) return 0;
    return (fact[n] * inversed[r] * inversed[n - r]);
  }
  mint npr(int n, int r) { return (fact[n] * inversed[n - r]); }
  mint nhr(int n, int r) {
    assert(n + r - 1 < (int)fact.size());
    return ncr(n + r - 1, r);
  }
};

mint ncr(int n, int r) {
  mint res = 1;
  for (int i = n - r + 1; i <= n; i++) res *= i;
  for (int i = 1; i <= r; i++) res /= i;
  return res;
}
template <typename T>
std::vector<T> get_divisors(T x, bool sorted = true) {
  std::vector<T> res;
  for (T i = 1; i <= x / i; i++)
    if (x % i == 0) {
      res.push_back(i);
      if (i != x / i) res.push_back(x / i);
    }
  if (sorted) std::sort(res.begin(), res.end());
  return res;
}
template <typename T>
struct FenwickTree {
  std::vector<T> bit;
  int n;
  FenwickTree(int _n) : n(_n), bit(_n) {}

  T sum(int r) {
    int ret = 0;
    for (; r >= 0; r = (r & (r + 1)) - 1) ret += bit[r];
    return ret;
  }

  T sum(int l, int r) {
    assert(l <= r);
    return sum(r) - sum(l - 1);
  }  // [l, r]

  void add(int idx, int delta) {
    for (; idx < n; idx = idx | (idx + 1)) bit[idx] += delta;
  }
};
template <typename T>
struct DSU {
  std::vector<T> f, siz;
  DSU(int n) : f(n), siz(n, 1) { std::iota(f.begin(), f.end(), 0); }
  T leader(T x) {
    while (x != f[x]) x = f[x] = f[f[x]];
    return x;
  }
  bool same(T x, T y) { return leader(x) == leader(y); }
  bool merge(T x, T y) {
    x = leader(x);
    y = leader(y);
    if (x == y) return false;
    siz[x] += siz[y];
    f[y] = x;
    return true;
  }
  T size(int x) { return siz[leader(x)]; }
};
void solve() {
  long long n, m;
  std::cin >> n >> m;

  std::vector dp(m, std::vector(3, (mint)0));
  dp[0][0] = 1;
  dp[0][1] = (mint)n;
  dp[0][2] = (n < 4) ? 0 : (mint)n * (n - 1) / 2 - n;
  for (int i = 0; i < m - 1; i++) {
    dp[i + 1][0] = dp[i][0] + dp[i][1] + dp[i][2];
    dp[i + 1][1] = dp[i][0] * n + dp[i][1] * (n - 1) + dp[i][2] * (n - 2);
    if (n < 4)
      dp[i + 1][2] = 0;
    else {
      dp[i + 1][2] += dp[i][0] * (n * (n - 1) / 2 - n);
      dp[i + 1][2] += dp[i][1] * ((n - 1) * (n - 2) / 2 - (n - 2));
      dp[i + 1][2] += dp[i][2] * ((n - 2) * (n - 3) / 2 - (n - 4));
    }
  }
  std::cout << dp[m - 1][0] + dp[m - 1][1] + dp[m - 1][2] << '\n';
}
int main() {
  std::ios_base::sync_with_stdio(false);
  std::cin.tie(nullptr);
  int t = 1;
  std::cin >> t;
  while (t--) solve();
}