from sys import stdin
def input():
    return stdin.readline().rstrip("\n")
mod = 998244353

def solve(a, b, k):
    if a == 0:
        return 0
    if k == 1:
        return max(a, 0)
    if b == 0 or b == 1:
        if a <= 0:
            return 0
        else:
            return a * k % mod
    if b > 1:
        if a <= 0:
            return 0
        # 1 * a + (k-1) * b
        return a * pow(b, k - 1, mod) % mod
    if b == -1:
        if a > 0:
            return a * k % mod
        else:
            return -a * (k - 1) % mod

    kh = (k - 1) // 2
    b2 = b * b
    if a > 0:
        if k % 2 == 0:
            return a * 2 * pow(b2, kh, mod) % mod
        else:
            return a * pow(b2, kh, mod) % mod
    if k % 2 == 0:
        return a * pow(b, k - 1, mod) % mod
    else:
        return a * 2 * pow(b, k - 2, mod) % mod

if __name__ == "__main__":
    case_t = 1
    case_t = int(input())
    for _ in [None] * case_t:
        a, b, k = map(lambda s_: int(s_), input().split())
        print(solve(a, b, k) % mod)