#include <bits/stdc++.h>

using namespace std;

#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(a) a.begin(), a.end()
#define Sort(a) sort(a.begin(), a.end())
#define RSort(a) sort(a.rbegin(), a.rend())

typedef long long int ll;
typedef long double ld;
typedef vector<int> vi;
typedef vector<long long> vll;
typedef vector<char> vc;
typedef vector<string> vst;
typedef vector<double> vd;
typedef pair<long long, long long> P;

const long long INF = 0x1fffffffffffffff;
const long long MOD = 998244353;
const long double PI = acos(-1);
 
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
template<class T, class U> inline T vin(T& vec, U n) { vec.resize(n); for(int i = 0; i < (int) n; ++i) cin >> vec[i]; return vec; }
template<class T> inline void vout(T vec, string s = "\n"){ for(auto x : vec) cout << x << s; }
template<class... T> void in(T&... a){ (cin >> ... >> a); }
void out(){ cout << '\n'; }
template<class T, class... Ts> void out(const T& a, const Ts&... b){ cout << a; (cout << ... << (cout << ' ', b)); cout << '\n'; }
template<class T, class U> void inGraph(vector<vector<T>>& G, U n, U m, bool directed = false){ G.resize(n); for(int i = 0; i < m; i++){ int a, b; cin >> a >> b; a--, b--; G[a].push_back(b); if(!directed) G[b].push_back(a); } }

ll t;

void input(){
    in(t);
}

ll solve2(ll n, ll x){
    ll ans = 0;
    if(n < x){
        ans = n / 2 + n % 2;
        ans %= MOD;
        return ans;
    }

    // x <= n
    vll dp(n + 1);
    vll check(n + 1);
    for(int i = 1; i <= n; i++){
        if(i < x){
            if(i % 2){
                dp[i] = 1;
            }else{
                dp[i] = 0;
            }
        }else{
            if(dp[i - 1] == 0){
                dp[i] = 1;
                continue;
            }
            if(dp[i - x] == 0 && check[i - x] == 0){
                dp[i] = 1;
                check[x] = 1;
                continue;
            }
        }
    }
    for(int i = 1; i <= n; i++){
        if(dp[i]){
            ans++;
        }
    }
    return ans;
}

void solve(){
    ll n, x; in(n, x);
    ll ans = 0;
    if(n < x){
        ans = n / 2 + n % 2;
        ans %= MOD;
        out(ans);
        return;
    }

    // x <= n
    if(x % 2 == 1){
        ans = n / 2 + n % 2;
    }else{
        ans = (x - 1) / 2 + (x - 1) % 2;
        n -= x - 1;
        ll d = n / (x + 1), m = n % (x + 1);
        ans += d * (x + 2) / 2;
        ans += m / 2 + m % 2;
    }
    ans %= MOD;
    out(ans);
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    
    input();
    while(t--) solve();
}