#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;

constexpr int FACT_SIZE = 1000000;
mint Fact[FACT_SIZE + 1];
mint iFact[FACT_SIZE + 1];
mint pow2[FACT_SIZE + 1];
const auto fact_init = [] {
    pow2[0] = 1;
    for(int i = 0; i < FACT_SIZE; i++) pow2[i + 1] = pow2[i] * 2;
    Fact[0] = mint::raw(1);
    for(int i = 1; i <= FACT_SIZE; ++i) {
        Fact[i] = Fact[i-1] * i;
    }
    iFact[FACT_SIZE] = Fact[FACT_SIZE].inv();
    for(int i = FACT_SIZE; i; --i) {
        iFact[i-1] = iFact[i] * i;
    }
    return false;
}();

mint comb(int n, int k) {
    if (k == 0) return mint::raw(1);
    assert(n >= 0 && k >= 0);
    if (k > n) return mint::raw(0);
    return Fact[n] * iFact[n - k] * iFact[k];
}

mint icomb(int n, int k) {
    return iFact[n] * Fact[n - k] * Fact[k];
}

mint fact(int n) {return Fact[n];}
mint perm(int n, int k) {
    assert(0 <= n);
    return Fact[n] * iFact[n - k];
}

} int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int t;
  cin >> t;
  vector<tuple<int, int, int>> qs;
  rep(i, t) {
    int n, m;
    cin >> n >> m;
    qs.emplace_back(n - 1, m - 1, i);
  }
  constexpr int B = 450;
  sort(all(qs), [](tuple<int, int, int> x, tuple<int, int, int> y) {
    int bx = get<0>(x) / B;
    int by = get<0>(y) / B;
    if (bx != by) return bx < by;
    else return get<1>(x) < get<1>(y);
  });
  mint v = 1;
  const mint inv2 = mint(2).inv();
  auto add1 = [&](int n, int m) {
    v *= 2;
    if (n >= m) v -= comb(n, m);
  };
  auto sub1 = [&](int n, int m) {
    if (n > m) v += comb(n - 1, m);
    v *= inv2;
  };
  auto add2 = [&](int n, int m) {
    v += comb(n, m + 1);
  };
  auto sub2 = [&](int n, int m) {
    v -= comb(n, m);
  };
  int n = 0, m = 0;
  vector<mint> ans(t);
  for(auto [ni, mi, i]: qs) {
    while(n < ni) add1(n++, m);
    while(m < mi) add2(n, m++);
    while(m > mi) sub2(n, m--);
    while(n > ni) sub1(n--, m);
    ans[i] = (pow2[ni + 1] - 1) * v;
  }
  rep(i, t) cout << ans[i].val() << '\n';
}