#include<bits/stdc++.h>
using namespace std;
using ll=long long;
#define rep(i,n) for(int i=0;i<n;i++)
#define rrep(i,n) for(int i=(n)-1;i>=0;i--)
#define all(v) v.begin(),v.end()
#define rall(v) v.rbegin(),v.rend()
template<class T> bool chmax(T &a, T b){if (a < b){a = b;return true;} else return false;}
template<class T> bool chmin(T &a, T b){if (a > b){a = b;return true;} else return false;}

const ll MOD=998244353;

void solve(){
    ll n,x;
    cin>>n>>x;
    ll ans;
    if(x%2==1){
        ans=(n+1)/2;
    }else{
        if(n<x)ans=(n+1)/2;
        else if(x==2||x==4){
            ans=x/2;
            n-=x-1;
            ans+=(n+1)/2;
        }else{
            ans=x/2;
            n-=x-1;
            ans+=(n/(x+3))*(x/2+2);
            n%=x+3;
            ans+=(n+1)/2;
        }
    }
    ans%=MOD;
    cout<<ans<<"\n";
}

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