a, b, c = map(int, input().split())
# (l, r]
l = 0
r = 10 ** 18
while r - l > 1 :
	m = (l + r) // 2
	d = (m // a) * b + (m - (m // a))

	if d >= c :
		r = m
	else :
		l = m

print(r)