#include <bits/stdc++.h>

using namespace std;

const int mod = 998244353;

using ll = long long;

ll solve(ll n, ll x) {
	if(x & 1 or n < x) return (n + 1) / 2 % mod;
	//特殊なindex を削る
	//x,2x+3,3x+6,...
	ll sp = (n - x) / (x + 3) + 1;
	return ((n - sp + 1) / 2 + sp) % mod;
}

int main() {
	int t;
	cin >> t;
	while(t--) {
		ll n, x;
		cin >> n >> x;
		cout << solve(n, x) << '\n';
	}
}