t=int(input())
for _ in range(t):
ins = list(map(int,input().split()))
i = ins[0]
d = ins[1]
z = ins[2]
zor_leaps = list(range(i,999,d))
zan_leaps = list(range(0,999,z))
neg_arr = []
for el in zor_leaps:
if el%z == 0:
print(zan_leaps.index(el))
break
else:
neg_arr.append(el)
if len(neg_arr) == len(zor_leaps):
print(-1)
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