N, P = map(int, input().split())
A = list(map(int, input().split()))
ans, temp, M = 0, P, max(A)
while temp <= M:
	d = {}
	for i in A:
		d[i % temp] = d.get(i % temp, 0) + 1
	for i in d:
		ans += d[i] * (d[i] - 1) // 2
	temp *= P
print(ans)