MOD = 998244353


def solve():
    A, B, K = [int(s) for s in input().split()]

    if K == 1:
        print(max(A, 0) % MOD)
        return

    if A == 0:
        print(0)
        return

    if 0 <= B <= 1:
        if A > 0:
            print(A * K % MOD)
        else:
            print(0)
        return

    if B == -1:
        if A > 0:
            print(A * K % MOD)
        else:
            print(A * (K - 1) * (-1) % MOD)

    if B >= 2:
        if A > 0:
            print(A * pow(B, K - 1, MOD) % MOD)
        else:
            print(0)
        return

    if A > 0:
        if K % 2 == 0:
            print(2 * A * pow(B, K - 2, MOD) % MOD)
        else:
            print(A * pow(B, K - 1, MOD) % MOD)
    else:
        if K % 2 == 0:
            print(A * pow(B, K - 1, MOD) % MOD)
        else:
            print(2 * A * pow(B, K - 2, MOD) % MOD)


if __name__ == "__main__":
    T = int(input())

    for _ in range(T):
        solve()