N,P=map(int, input().split())
A=list(map(int, input().split()))
ans=0
for i in range(1,100):
  D={}
  PP=pow(P,i)
  for a in A:
    b=a%PP 
    if b not in D:
      D[b]=0
    D[b]+=1
  for d in D:
    ans+=D[d]*(D[d]-1)
print(ans//2)