#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <chrono>
#include <cmath>
#include <complex>
#include <deque>
#include <forward_list>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iostream>
#include <limits>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <tuple>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
using namespace std;
using lint = long long;

map<tuple<int, int, bool, bool>, bool> memo;

bool rec(int N, int X, bool a_done, bool b_done) {
    if (N < X) return N % 2 ? true : false;

    const auto tpl = make_tuple(N, X, a_done, b_done);
    if (memo.count(tpl)) return memo[tpl];

    bool ret = false;
    if (!rec(N - 1, X, b_done, false)) ret = true;
    if (!a_done and !rec(N - X, X, b_done, true)) ret = true;
    return memo[tpl] = ret;
}

bool experiment(int N, int X) { return rec(N, X, false, false); }

lint solve(lint N, lint X) {
    if (X % 2 == 1) return (N + 1) / 2;

    lint rec = X + 3;
    lint len = N + 1;

    lint ret = len / rec * ((rec + 1) / 2), md = len % rec;
    ret += md / 2;
    if (md + 2 == rec) ++ret;
    return ret;
}

int main() {
    cin.tie(nullptr), ios::sync_with_stdio(false);
    int T;
    cin >> T;
    while (T--) {
        lint N, X;
        cin >> N >> X;
        cout << solve(N, X) % 998244353 << '\n';
    }
}