#define _USE_MATH_DEFINES #include using namespace std; #define FOR(i,m,n) for(int i=(m);i<(n);++i) #define REP(i,n) FOR(i,0,n) #define ALL(v) (v).begin(),(v).end() using ll = long long; constexpr int INF = 0x3f3f3f3f; constexpr long long LINF = 0x3f3f3f3f3f3f3f3fLL; constexpr double EPS = 1e-8; constexpr int MOD = 998244353; constexpr int DY[]{1, 0, -1, 0}, DX[]{0, -1, 0, 1}; constexpr int DY8[]{1, 1, 0, -1, -1, -1, 0, 1}, DX8[]{0, -1, -1, -1, 0, 1, 1, 1}; template inline bool chmax(T &a, U b) { return a < b ? (a = b, true) : false; } template inline bool chmin(T &a, U b) { return a > b ? (a = b, true) : false; } struct IOSetup { IOSetup() { std::cin.tie(nullptr); std::ios_base::sync_with_stdio(false); std::cout << fixed << setprecision(20); } } iosetup; template struct MInt { unsigned int val; MInt(): val(0) {} MInt(long long x) : val(x >= 0 ? x % M : x % M + M) {} static constexpr int get_mod() { return M; } static void set_mod(int divisor) { assert(divisor == M); } static void init(int x = 10000000) { inv(x, true); fact(x); fact_inv(x); } static MInt inv(int x, bool init = false) { // assert(0 <= x && x < M && std::__gcd(x, M) == 1); static std::vector inverse{0, 1}; int prev = inverse.size(); if (init && x >= prev) { // "x!" and "M" must be disjoint. inverse.resize(x + 1); for (int i = prev; i <= x; ++i) inverse[i] = -inverse[M % i] * (M / i); } if (x < inverse.size()) return inverse[x]; unsigned int a = x, b = M; int u = 1, v = 0; while (b) { unsigned int q = a / b; std::swap(a -= q * b, b); std::swap(u -= q * v, v); } return u; } static MInt fact(int x) { static std::vector f{1}; int prev = f.size(); if (x >= prev) { f.resize(x + 1); for (int i = prev; i <= x; ++i) f[i] = f[i - 1] * i; } return f[x]; } static MInt fact_inv(int x) { static std::vector finv{1}; int prev = finv.size(); if (x >= prev) { finv.resize(x + 1); finv[x] = inv(fact(x).val); for (int i = x; i > prev; --i) finv[i - 1] = finv[i] * i; } return finv[x]; } static MInt nCk(int n, int k) { if (n < 0 || n < k || k < 0) return 0; if (n - k > k) k = n - k; return fact(n) * fact_inv(k) * fact_inv(n - k); } static MInt nPk(int n, int k) { return n < 0 || n < k || k < 0 ? 0 : fact(n) * fact_inv(n - k); } static MInt nHk(int n, int k) { return n < 0 || k < 0 ? 0 : (k == 0 ? 1 : nCk(n + k - 1, k)); } static MInt large_nCk(long long n, int k) { if (n < 0 || n < k || k < 0) return 0; inv(k, true); MInt res = 1; for (int i = 1; i <= k; ++i) res *= inv(i) * n--; return res; } MInt pow(long long exponent) const { MInt tmp = *this, res = 1; while (exponent > 0) { if (exponent & 1) res *= tmp; tmp *= tmp; exponent >>= 1; } return res; } MInt &operator+=(const MInt &x) { if((val += x.val) >= M) val -= M; return *this; } MInt &operator-=(const MInt &x) { if((val += M - x.val) >= M) val -= M; return *this; } MInt &operator*=(const MInt &x) { val = static_cast(val) * x.val % M; return *this; } MInt &operator/=(const MInt &x) { return *this *= inv(x.val); } bool operator==(const MInt &x) const { return val == x.val; } bool operator!=(const MInt &x) const { return val != x.val; } bool operator<(const MInt &x) const { return val < x.val; } bool operator<=(const MInt &x) const { return val <= x.val; } bool operator>(const MInt &x) const { return val > x.val; } bool operator>=(const MInt &x) const { return val >= x.val; } MInt &operator++() { if (++val == M) val = 0; return *this; } MInt operator++(int) { MInt res = *this; ++*this; return res; } MInt &operator--() { val = (val == 0 ? M : val) - 1; return *this; } MInt operator--(int) { MInt res = *this; --*this; return res; } MInt operator+() const { return *this; } MInt operator-() const { return MInt(val ? M - val : 0); } MInt operator+(const MInt &x) const { return MInt(*this) += x; } MInt operator-(const MInt &x) const { return MInt(*this) -= x; } MInt operator*(const MInt &x) const { return MInt(*this) *= x; } MInt operator/(const MInt &x) const { return MInt(*this) /= x; } friend std::ostream &operator<<(std::ostream &os, const MInt &x) { return os << x.val; } friend std::istream &operator>>(std::istream &is, MInt &x) { long long val; is >> val; x = MInt(val); return is; } }; namespace std { template MInt abs(const MInt &x) { return x; } } using ModInt = MInt; int main() { constexpr int N = 4000; ModInt dp[N + 1][N + 1]{}; fill(dp[0], dp[0] + (N + 1), 1); FOR(i, 1, N + 1) { dp[i][0] = 1; FOR(j, 1, N + 1) dp[i][j] = dp[i - 1][j] + dp[i][j - 1] + dp[i - 1][j - 1] * 2; } FOR(i, 1, N + 1) FOR(j, 1, N + 1) dp[i][j] += dp[i - 1][j - 1]; int q; cin >> q; while (q--) { int x, y; cin >> x >> y; cout << dp[x][y] << '\n'; } return 0; }