#include <bits/stdc++.h>
using namespace std;
#if __has_include(<atcoder/all>)
    #include <atcoder/all>
using namespace atcoder;
#endif
template<class T, class... Ts> void print(const T& a, const Ts&... b){cout << a;(cout << ... << (cout << ' ', b));cout << '\n';}
template<class... T> void input(T&... a){(cin >> ... >> a);}
void print(){cout << '\n';}
typedef long long ll;
typedef long double ld;
typedef pair<ll, ll> P;
typedef tuple<ll, ll, ll> T;
typedef modint998244353 mint;
#define rep(i, n) for(ll i = 0; i < n; i++)

int main() {
    cin.tie(nullptr);
    ios_base::sync_with_stdio(false);
    
    ll t; input(t);
    while(t--){
        ll n,x; input(n,x);
        mint ans = 0;
        if(x%2 == 1){
            ans = (n+1)/2;
            // print((n%2 == 1 ? "Alice" : "Bob")),0;
        }
        else {
            ans = (n/(x+1))*(x/2+1) + ((n%(x+1))+1)/2 + ((n%(x+1)) == x ? 1 : 0);
            // if(n%x == 0)print("Alice");
            // else print( ((n%(x-1))%2 == 1 ? "Alice" : "Bob") );
        }
        print(ans.val());
    }
    
    return 0;
}