## https://yukicoder.me/problems/no/3462

from collections import deque

MOD = 998244353

def solve(A, B, K):
    if A > 0:
        if B > 1:
            answer = A
            answer *= pow(B, K - 1, MOD)
            answer %= MOD
        elif -1 <= B <= 1:
            answer = (K * A) % MOD
        else:
            if K % 2 == 1:
                answer = A
                answer *= pow(B, K - 1, MOD)
                answer %= MOD
            else:
                answer = (2 * A) % MOD
                answer *= pow(B, K - 2, MOD)
                answer %= MOD
    elif A == 0:
        answer = 0
    else:
        if B >= 0:
            answer = 0
        elif B == -1:
            answer = abs(A) * (K - 1)
            answer %= MOD
        else:
            if K % 2 == 0:
                answer = A
                answer *= pow(B, K - 1, MOD)
                answer %= MOD
            elif K % 2 == 1:
                if K == 1:
                    answer = 0
                else:
                    answer = (2 * A) % MOD
                    answer *= pow(B, K - 2, MOD)
                    answer %= MOD
    return answer


def solve2(A, B, K):
    answer = 0
    for k in range(1, K + 1):
        for bit in range(2 ** k):
            x = 0
            for i in range(k):
                if bit & (1 << i) > 0:
                    x *= B
                else:
                    x += A
            answer = max(answer, x)
    print("judge = ", answer % MOD)
                




def main():
    T = int(input())
    answers = []
    for _ in range(T):
        A, B, K = map(int, input().split())
        ans = solve(A, B, K)
#        solve2(A, B, K)
        answers.append(ans)

    for ans in answers:
        print(ans)

if __name__ == "__main__":
    main()