#include<bits/stdc++.h>
namespace {
#pragma GCC diagnostic ignored "-Wunused-function"
#include<atcoder/all>
#pragma GCC diagnostic warning "-Wunused-function"
using namespace std;
using namespace atcoder;
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; i--)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; }
template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; }
using ll = long long;
using P = pair<int,int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;
using mint = modint998244353;

template<class T, T (*add)(T, T), T (*zero)(), T (*mul)(T, T), T (*one)(), int N>
struct Mat : array<array<T, N>, N> {
  using M = Mat<T, add, zero, mul, one, N>;
  void make_identity() {
    for (int i = 0; i < N; i++) {
      for (int j = 0; j < N; j++) {
        (*this)[i][j] = zero();
      }
    }
    for (int i = 0; i < N; i++) {
      (*this)[i][i] = one();
    }
  }
  M& operator+=(const M& rhs) {
    for (int i = 0; i < N; i++) {
      for (int j = 0; j < N; j++) {
        (*this)[i][j] = add((*this)[i][j], rhs[i][j]);
      }
    }
    return *this;
  }
  M& operator*=(const M& rhs) {
    static M temp;
    for (int i = 0; i < N; i++) {
      for (int j = 0; j < N; j++) {
        temp[i][j] = zero();
      }
    }
    for (int i = 0; i < N; i++) {
      for (int j = 0; j < N; j++) {
        for (int k = 0; k < N; k++) {
          temp[i][k] = add(temp[i][k], mul((*this)[i][j], rhs[j][k]));
        }
      }
    }
    *this = temp;
    return *this;
  }
  M operator*(const M& rhs) {
    M res = *this;
    res *= rhs;
    return res;
  }
  template <class I>
  void inplace_pow(I k) {
    assert(k >= 0);
    static M temp;
    temp = *this;
    make_identity();
    while (k) {
      if (k & 1) *this *= temp;
      k >>= 1;
      if (k) temp *= temp;
    }
  }
  friend ostream& operator<<(ostream& os, const M& A) {
    for (int i = 0; i < N; i++) {
      for (int j = 0; j < N; j++) {
        os << A[i][j] << " \n"[j + 1 == N];
      }
    }
    return os;
  }
};

// mint
mint add(mint x, mint y) { return x + y; }
mint zero() { return mint(); }
mint mul(mint x, mint y) { return x * y; }
mint one() { return mint::raw(1); }
using M = Mat<mint, add, zero, mul, one, 2>;

} int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  constexpr int SZ = 10000010;
  vector<M> memo1(SZ), memo2(SZ);
  rep(i, SZ) {
    memo1[i][0] = {2 * (i + 1), i + 1};
    memo1[i][1] = {1, 0};
    memo2[i][0] = {2 * i, i - 1};
    memo2[i][1] = {1, 0};
  }
  rep(i, SZ - 1) {
    M t = memo1[i];
    t *= memo1[i + 1];
    memo1[i + 1] = t;
  }
  for (int i = 2; i < SZ; i++) {
    memo2[i] *= memo2[i - 1];
  }
  int tt;
  cin >> tt;
  while(tt--) {
    ll n, m;
    cin >> n >> m;
    if (n > m) swap(n, m);
    if (n == 0) {
      cout << 1 << '\n';
      continue;
    }
    M b;
    b[0] = {2 * n + 1, n};
    b[1] = {1, 0};
    b.inplace_pow(m - n);
    M a = memo1[n - 1] * b * memo2[n];
    mint ans = a[0][0];
    cout << ans.val() << '\n';
  }

}