from collections import defaultdict

N,P=map(int,input().split())
A=list(map(int,input().split()))

ANS=0

x=P

while x<10**9:
    LIST=defaultdict(list)

    for a in A:
        LIST[a%x].append(a)

    for k in LIST:
        L=len(LIST[k])
        ANS+=L*(L-1)//2

    #print(LIST)

    x*=P

print(ANS)