def main():
    from sys import stdin, setrecursionlimit
    # setrecursionlimit(1000000)
    input = stdin.readline
    def iinput(): return int(input())
    def sinput(): return input().rstrip()
    def i0input(): return int(input()) - 1
    def linput(): return list(input().split())
    def liinput(): return list(map(int, input().split()))
    def miinput(): return map(int, input().split())
    def li0input(): return list(map(lambda x: int(x) - 1, input().split()))
    def mi0input(): return map(lambda x: int(x) - 1, input().split())
    INF = 1000000000000000000
    MOD = 998244353

    T = iinput()
    for _ in [0] * T:
        N, X = miinput()
        if X % 2:
            ans = (N + 1) // 2
            ans %= MOD
            print(ans)
        else:
            ans = (N + 1) // (2 * X) * X
            tmp = (N + 1) // X % 2
            if tmp:
                ans += ((N + 1) % X + 1) // 2
            else:
                ans += (N + 1) % X // 2
            ans %= MOD
            print(ans)
main()