from collections import deque, defaultdict, Counter
from bisect import bisect_left, bisect_right
from itertools import permutations, combinations, groupby
from heapq import heappop, heappush
import math, sys
input = lambda: sys.stdin.readline().rstrip("\r\n")
def printl(li, sep=" "): print(sep.join(map(str, li)))
def yn(flag): print(Yes if flag else No)
_int = lambda x: int(x)-1
MOD = 998244353 #10**9+7
INF = 1<<60
Yes, No = "Yes", "No"

def solve():
    A, B, K = map(int, input().split())
    if A == 0:
        print(0)
        return
    if 0 <= B <= 1:
        if A < 0:
            print(0)
        else:
            print(A*K)
        return
    if B == -1:
        if A < 0:
            print(-A*(K-1))
        else:
            print(A*K)
        return
    if B > 1:
        if A < 0:
            print(0)
        else: # A > 0
            print(A*pow(B, K-1, MOD)%MOD)
    else: # B < -1
        if A < 0:
            if K&1:
                if K == 1:
                    print(0)
                else:
                    print(-A*2*pow(-B, K-2, MOD)%MOD)
            else:
                print(-A*pow(-B, K-1, MOD)%MOD)
        else:
            if K&1:
                print(A*pow(-B, K-1, MOD)%MOD)
            else:
                print(A*2*pow(-B, K-2, MOD)%MOD)
        return

for _ in range(int(input())):
    solve()