A,B,C=gets.split.map(&:to_i)

L = 0
R = 10000000000000000000

while(R-L>1)
	mid = (L+R)/2
	res = (mid/A)*B + (mid/A)*(A-1) + (mid%A)

	if res >= C
		R = mid
	else
		L = mid
	end
end

puts R