#pragma GCC optimize("Ofast") #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx") #pragma GCC optimize("unroll-loops") //#pragma warning(disable : 4996) //#define ATCODER #ifdef ATCODER #include using namespace atcoder; #endif #include #include #include #ifdef _MSC_VER #include #define __builtin_popcount __popcnt #define __builtin_popcountll __popcnt64 #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; #define REP(i, n) for (int i = 0; i < (n); ++i) #define REPR(i, n) for (int i = n - 1; i >= 0; --i) #define FOR(i, m, n) for (int i = m; i < n; ++i) #define FORR(i, m, n) for (int i = m - 1; i >= n; --i) #define SORT(v, n) sort(v, v + n); #define VSORT(v) sort(v.begin(), v.end()); #define REVERSE(v, n) reverse(v, v + n); #define VREVERSE(v) reverse(v.begin(), v.end()) #define ll long long #define print(x) cout << (x) << '\n' #define pe(x) cout << (x) << " " #define DEBUG(x) cout << #x << ": " << x << endl #define lb(v, n) lower_bound(v.begin(), v.end(), (n)) #define ub(v, n) upper_bound(v.begin(), v.end(), (n)) #define int long long //#define double long double #define all(x) (x).begin(), (x).end() #define print_space(v) REP(i, v.size()) cout << v[i] << " \n"[i==(int)v.size()-1] template inline void chmin(T1 & a, T2 b) { if (a > b) a = b; } template inline void chmax(T1& a, T2 b) { if (a < b) a = b; } typedef pair pii; typedef pair pll; std::random_device rd; std::mt19937 mt(rd()); constexpr ll MOD = 998244353; constexpr int MAX = 440000; const double pi = acos(-1); constexpr double EPS = 1e-8; constexpr ll LINF = 1e17 + 1; constexpr int INF = 1e9 + 1; long long fac[MAX], finv[MAX], inv[MAX]; // テーブルを作る前処理 void COMinit() { fac[0] = fac[1] = 1; finv[0] = finv[1] = 1; inv[1] = 1; for (int i = 2; i < MAX; i++) { fac[i] = fac[i - 1] * i % MOD; inv[i] = MOD - inv[MOD%i] * (MOD / i) % MOD; finv[i] = finv[i - 1] * inv[i] % MOD; } } // 二項係数計算 long long COM(int n, int k) { if (n < k) return 0; if (n < 0 || k < 0) return 0; return fac[n] * (finv[k] * finv[n - k] % MOD) % MOD; } ll add(ll x, ll y) { x += y; if (x >= MOD) return x - MOD; return x; } ll sub(ll x, ll y) { x -= y; if (x < 0) return x + MOD; return x; } ll mult(ll x, ll y) { return (x * y) % MOD; } ll bin_pow(ll x, ll p) { if (p == 0) return 1; if (p & 1) return mult(x, bin_pow(x, p - 1)); return bin_pow(mult(x, x), p / 2); } //const int mod = 1000000007; const int mod = 998244353; struct mint { ll x; // typedef long long ll; mint(ll x = 0) :x((x%mod + mod) % mod) {} mint operator-() const { return mint(-x); } mint& operator+=(const mint a) { if ((x += a.x) >= mod) x -= mod; return *this; } mint& operator-=(const mint a) { if ((x += mod - a.x) >= mod) x -= mod; return *this; } mint& operator*=(const mint a) { (x *= a.x) %= mod; return *this; } mint operator+(const mint a) const { return mint(*this) += a; } mint operator-(const mint a) const { return mint(*this) -= a; } mint operator*(const mint a) const { return mint(*this) *= a; } mint pow(ll t) const { if (!t) return 1; mint a = pow(t >> 1); a *= a; if (t & 1) a *= *this; return a; } // for prime mod mint inv() const { return pow(mod - 2); } mint& operator/=(const mint a) { return *this *= a.inv(); } mint operator/(const mint a) const { return mint(*this) /= a; } }; istream& operator>>(istream& is, const mint& a) { return is >> a.x; } ostream& operator<<(ostream& os, const mint& a) { return os << a.x; } void solve() { mint t = 2; int N, K; cin >> N >> K; mint ans = (t.pow(K*N)-t.pow(K*(N - 1)))*N; print(ans); } signed main() { cin.tie(0); ios::sync_with_stdio(false); int q; cin >> q; while (q--) solve(); }