#include <cassert>
#include <cstdint>
#include <iostream>
#include <utility>
#include <vector>

#include <atcoder/modint>

namespace emthrm {

template <typename T>
struct Matrix {
  explicit Matrix(const int m, const int n, const T def = 0)
      : data(m, std::vector<T>(n, def)) {}

  int nrow() const { return data.size(); }
  int ncol() const { return data.front().size(); }

  Matrix pow(long long exponent) const {
    const int n = nrow();
    Matrix<T> res(n, n, 0), tmp = *this;
    for (int i = 0; i < n; ++i) {
      res[i][i] = 1;
    }
    for (; exponent > 0; exponent >>= 1) {
      if (exponent & 1) res *= tmp;
      tmp *= tmp;
    }
    return res;
  }

  inline const std::vector<T>& operator[](const int i) const { return data[i]; }
  inline std::vector<T>& operator[](const int i) { return data[i]; }

  Matrix& operator=(const Matrix& x) = default;

  Matrix& operator+=(const Matrix& x) {
    const int m = nrow(), n = ncol();
    for (int i = 0; i < m; ++i) {
      for (int j = 0; j < n; ++j) {
        data[i][j] += x[i][j];
      }
    }
    return *this;
  }

  Matrix& operator-=(const Matrix& x) {
    const int m = nrow(), n = ncol();
    for (int i = 0; i < m; ++i) {
      for (int j = 0; j < n; ++j) {
        data[i][j] -= x[i][j];
      }
    }
    return *this;
  }

  Matrix& operator*=(const Matrix& x) {
    const int m = nrow(), l = ncol(), n = x.ncol();
    std::vector<std::vector<T>> res(m, std::vector<T>(n, 0));
    for (int i = 0; i < m; ++i) {
      for (int k = 0; k < l; ++k) {
        for (int j = 0; j < n; ++j) {
          res[i][j] += data[i][k] * x[k][j];
        }
      }
    }
    data.swap(res);
    return *this;
  }

  Matrix operator+(const Matrix& x) const { return Matrix(*this) += x; }
  Matrix operator-(const Matrix& x) const { return Matrix(*this) -= x; }
  Matrix operator*(const Matrix& x) const { return Matrix(*this) *= x; }

 private:
  std::vector<std::vector<T>> data;
};

}  // namespace emthrm

using mint = atcoder::modint998244353;

// <TLE>
// O(min(n, m) + log|n - m|) 時間
mint Solve(const int n, const std::int64_t m) {
  if (n > m) return Solve(m, n);

  mint dp0 = 1, dp1 = 0;
  for (int diag = 0; diag < n; ++diag) {
    dp1 += dp0 * (diag + 1) * 2;
    dp0 *= diag + 1;
    std::swap(dp0, dp1);
  }
  emthrm::Matrix<mint> matrix(2, 2);
  matrix[0][0] = n * 2 + 1;
  matrix[0][1] = 1;
  matrix[1][0] = n;
  matrix = matrix.pow(m - n);
  const mint next_dp0 = dp0 * matrix[0][0] + dp1 * matrix[0][1];
  const mint next_dp1 = dp0 * matrix[1][0] + dp1 * matrix[1][1];
  dp0 = next_dp0;
  dp1 = next_dp1;
  for (std::int64_t diag = m; diag < n + m; ++diag) {
    dp1 += dp0 * (n + m - diag) * 2;
    dp0 *= n + m - diag - 1;
    std::swap(dp0, dp1);
  }
  return dp0;
}

int main() {
  constexpr int kMaxT = 20000, kMaxN = 10000000;
  constexpr std::int64_t kMaxM = 1000000000000000000;

  int t;
  std::cin >> t;
  assert(1 <= t && t <= kMaxT);

  while (t--) {
    int n;
    std::int64_t m;
    std::cin >> n >> m;
    assert(0 <= n && n <= kMaxN && 0 <= m && m <= kMaxM);
    std::cout << Solve(n, m).val() << '\n';
  }
  return 0;
}