MOD = 998244353
def solve(A,B,K):
    if B==0:
        if A > 0:
            return A*K % MOD
        else:
            return 0
    if B==1:
        if A > 0:
            return A*K % MOD
        else:
            return 0
    if B==-1:
        if A > 0:
            return A*K % MOD
        else:
            return (-1 * A * (K-1)) % MOD
    if B > 1:
        if A >= 2:
            return A * pow(B,K-1,MOD) % MOD
        elif A == 1:
            return A * K % MOD
        else:
            return 0
    assert B <= -2
    if A >= 2:
        if K%2:
            return A * pow(B,K-1,MOD) % MOD
        else:
            return (A+A) * pow(B,K-2,MOD) % MOD
    elif A == 1:
        return 1
    elif A == 0:
        return 0
    elif A == -1:
        return 1 if K>=2 else 0
    else:
        assert A <= -2
        if K%2:
            return (A+A) * pow(B,K-2,MOD) * MOD
        else:
            return A * pow(B,K-1,MOD) % MOD

T = int(input())
anss = []
for _ in range(T):
    A,B,K = map(int,input().split())
    anss.append(solve(A,B,K))
print(*anss, sep='\n')