import sys

# sys.setrecursionlimit(200005)
# sys.set_int_max_str_digits(200005)
int1 = lambda x: int(x)-1
pDB = lambda *x: print(*x, end="\n", file=sys.stderr)
p2D = lambda x: print(*x, sep="\n", end="\n\n", file=sys.stderr)
def II(): return int(sys.stdin.readline())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def LI1(): return list(map(int1, sys.stdin.readline().split()))
def LLI1(rows_number): return [LI1() for _ in range(rows_number)]
def SI(): return sys.stdin.readline().rstrip()

dij = [(0, 1), (-1, 0), (0, -1), (1, 0)]
# dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)]
# inf = -1-(-1 << 31)
inf = -1-(-1 << 62)

# md = 10**9+7
md = 998244353

def solve():
    a, b, k = LI()
    ans = 0
    if a < 0:
        if b == -1:
            ans = -a*(k-1)
        elif b < 0:
            y = k-1
            if y & 1 == 0: y -= 1
            if y > 0: ans = a*(k-y)*pow(b, y, md)%md
    elif a > 0:
        if b < -1:
            y = k-1
            if y & 1: y -= 1
            if y > 0:
                ans = a*(k-y)*pow(b, y, md)%md
            else:
                ans=a*k
        elif b > 1:
            ans = a*pow(b, k-1, md)%md
        else:
            ans = a*k
    print(ans%md)

for _ in range(II()): solve()