#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll myrand(ll B){
    return (unsigned long long) rng() % B;
}

constexpr ll mod = 998244353;

ll mod_pow(ll a,ll b){
    a%=mod;
    if(b==0)return 1;
    if(b==1)return a;
    ll res=mod_pow(a,b/2)%mod;
    res*=res; res%=mod;
    if(b%2)res*=a;
    return res%mod;
}

void add(int &x,int y){
    x += y;
    if(x >= mod) x -= mod;
}

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
//    for(int i=0;i<10;i++){
//        int n = myrand(30)+1, x = myrand(n)+1;
//        map<pair<int,pair<int,int>>,bool> mp;
//        auto slv = [&](auto self,int cur,int a,int b)->bool{
//            if(mp.find({cur,{a,b}}) != mp.end()){
//                return mp[{cur,{a,b}}];
//            }
//            bool res = false;
//            if(cur == 0) return false;
//            if(!self(self, cur-1, b, 0)){
//                res = true;
//            }
//            if(cur >= x and !a and !self(self, cur-x, b, 1)){
//                res = true;
//            }
//            mp[{cur,{a,b}}] = res;
//            return res;
//        };
//        cout << n << " " << x << endl;
//        for(int i=1;i<=n;i++){
//            cout << "i = " << i << " " << slv(slv,i,0,0) << endl;
//        }
//    }
    int q; cin >> q;
    while(q--){
        ll n,x; cin >> n >> x;
        ll res = (n+1)/2;
        ll ad = n/x - n/(2*x);
        if(x%2 == 0) res += ad;
        cout << res%mod << "\n";
    }
}