#include <bits/stdc++.h>

using namespace std;
#define rep(i,n) for(int i=0;i<n;++i)
#define rep1(i,n) for(int i=1;i<=n;++i)
#define rrep(i,n) for(int i=n-1;i>=0;--i)
#define debug(output) if(debugFlag)cout<<#output<<"= "<<output<<"\n";
using lint = long long;
typedef pair<int,int> P;
const bool debugFlag=true;
const lint linf=1.1e18;const int inf=1.01e9;
constexpr int MOD=1000000007;
template<class T>bool chmax(T &a, const T &b) { if(a < b){ a = b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if(a > b){ a = b; return 1; } return 0; }

#include<atcoder/all>
using namespace atcoder;
using mint = modint998244353;

void solve(){
    lint n,x;cin>>n>>x;
    mint res=0;
    if(x&1)res=(n+1)/2;
    else{
        if(n<x)res=(n+1)/2;
        else if(n==x){
            res=x/2+1;
        }
        else{
            res=x/2;
            n-=x-1;
            res+=n/(x+1)*(x/2+1);
            n%=x+1;
            res+=(n+1)/2;
        }
    }
    cout<<res.val()<<"\n";
}

signed main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    int t;cin>>t;
    rep(i,t)solve();
    return 0;
}