from sys import stdin
input = stdin.readline

MOD = 998244353

for _ in range(int(input())):
    A, B, K = map(int, input().split())

    if A == 0:
        print(0)
        continue

    if B == 0:
        if 0 <= A:
            print(A*K%MOD)
        else:
            print(0)
        continue

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