n = int(input())
m = int(input())
a = int(input())
if n >= 1 and n <= 10**9 and m >= 1 and m <= 10**9 and a >= 1 and a <= 10**9:
	if n%a == 0:
		a_length = n/a
	else:
		if (n/a - round(n/a)) > 0:
			a_length = round(n/a) + 1
		else:
			a_length = round(n/a)
	if m%a == 0:
		a_width = m/a
	else:
		if (m/a - round(m/a)) > 0:
			a_width = round(m/a) + 1
		else:
			a_width = round(m/a)
	if a_length > a_width:
		answer = a_length
	else:
		answer = a_width
	print(answer*answer)

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

NiA2IDQ=

6 6 4