from math import sqrt, ceil
from collections import defaultdict
N,P = map(int, input().split())
A = list(map(int, input().split()))
M = max(A)
ans = 0
for i in range(1, ceil(sqrt(M))+1):
    D = defaultdict(int)
    p = pow(P, i)
    for j in range(N):
        D[A[j] % p] += 1
    for v in D.values():
        ans += v*(v-1)//2
print(ans)