mod = 1000000007
eps = 10**-9


def main():
    import sys
    import math
    input = sys.stdin.readline

    inv = {1: 1, 3: 7, 7: 3, 9: 9}
    for _ in range(int(input())):
        a, b, c = map(int, input().split())
        q = pow(10, c, b)
        cnt2 = cnt5 = 0
        while b % 2 == 0:
            cnt2 += 1
            b //= 2
            q //= 2
        while b % 5 == 0:
            cnt5 += 1
            b //= 5
            q //= 5
        r = (pow(2, c - cnt2, 10) * pow(5, c - cnt5, 10)) % 10
        p = ((r-q) * inv[b % 10]) % 10
        ans0 = (a * p) % 10
        ans1 = math.floor(a * q / b) % 10
        print((ans0 + ans1) % 10)


if __name__ == '__main__':
    main()