#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<ll,ll>;
#define fix(x) fixed << setprecision(x)
#define asc(x) x, vector<x>, greater<x>
#define rep(i, n) for(ll i = 0; i < n; i++)
#define all(x) (x).begin(),(x).end()
template<class T>bool chmin(T&a, const T&b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool chmax(T&a, const T&b){if(a<b){a=b;return 1;}return 0;}
const ll MOD = 998244353;
int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int t;
    cin >> t;
    rep(houren,t){
        ll n, x, ans = 0;
        cin >> n >> x;
        if(x&1) ans = (n+1)/2;
        else{
            if(n<x) ans = (n+1)/2;
            else if(n<2*x+2) ans = n/2+1;
            else{
                ans = x+2;
                ans += (n - 2*x-2) / (x+3) * (x/2+2) + ((n - 2*x-2) % (x+3) + 1) / 2;
            }
        }
        cout << ans%MOD << '\n';
    }
    return 0;
}