from collections import Counter
n,p = map(int,input().split())
A = list(map(int,input().split()))

ma = max(A)

ans = 0
mod = 1
for i in range(30):
    mod *= p
    if mod > ma:
        break

    C = Counter([a%mod for a in A])
    # print(C)
    for v in C.values():
        ans += v*(v-1)//2
print(ans)