#include <bits/stdc++.h>
using namespace std;

constexpr int mod = 998244353;

bool dp[200200];

int main() {
    /*
    int X; // X は偶数
    cin >> X;
    for(int i = 1; i <= 100; i++) {
        if(i < X) {
            if(i%2 == 1) {
                dp[i] = true;
            }
            continue;
        }
        if(i == X) {
            dp[i] = true;
            continue;
        }
        if(i == X+1) {
            continue;
        }
        if(!dp[i-1]) {
            dp[i] = true;
            continue;
        }
        if(i == 2*X) {
            continue;
        }
        if(dp[i-X-2]) {
            continue;
        }
        if(i < 2*X) {
            dp[i] = true;
            continue;
        }
        if(i == 2*X+1) {
            dp[i] = true;
            continue;
        }
        if(dp[2*X-2]) {
            dp[i] = true;
        }
    }
    for(int i = X; i <= 30; i++) {
        if(dp[i]) {
            cout << i << endl;
        }
    }*/
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int t;
    cin >> t;
    while(t--) {
        long long n,x;
        cin >> n >> x;
        if(x%2 == 1) {
            cout << (n+1)/2%mod << "\n";
        }
        else {
            if(n < x) {
                cout << (n+1)/2%mod << "\n";
            }
            else {
                long long tmp = x/2+1;
                if(n >= x+2) {
                    long long tmp2 = (x/2+1)*2+1;
                    tmp += (n-x-2)/tmp2*(tmp2+1)/2;
                    tmp += (n-x-2)%tmp2/2+1;
                    if((n-x-2)%tmp2 == tmp2-2) {
                        tmp++;
                    }
                }
                tmp %= mod;
                cout << tmp << "\n";
            }
        }
    }
}