#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pll = pair<ll, ll>;
#define drep(i, cc, n) for (ll i = (cc); i <= (n); ++i)
#define rep(i, n) drep(i, 0, n - 1)
#define all(a) (a).begin(), (a).end()
#define pb push_back
#define fi first
#define se second

const ll MOD = 998244353;
const ll INF = 1LL << 60;
const ll MAX_N = 2e5;

ll solve(){
    ll n, x;
    cin >> n >> x;

    if(x%2 == 0){
        if(n < x){
            return ((n+1)/2)%MOD;
        }else{
            ll ans = x/2;
            ll q = n/x - 1;
            ll r = n%x;
            ans += q*(x/2) + r/2 + 1;
            return ans%MOD;
        }
    }else{
        if(n < x){
            return ((n+1)/2)%MOD;
        }else{
            ll ans = x/2;
            ll q = n/x - 1;
            ll r = n%x;
            ans += q*((x+1)/2) + r/2 + 1;
            return ans%MOD;
        }
    }
}

int main(){
    ll t;
    cin >> t;

    vector<ll> ans(t);
    rep(i, t) ans[i] = solve();
    rep(i, t) cout << ans[i] << endl;
}