from collections import defaultdict

N,P=map(int,input().split())
def solve(A):
  if len(A)==1:
    return 0
  dct=defaultdict(list)
  for a in A:
    dct[a%P].append(a)
  ans=0
  for a,A in dct.items():
    le=len(A)
    ans+=solve([(aa-a)//P for aa in A])+le*(le-1)//2
  return ans
A=list(map(int,input().split()))
ans=solve(A)
print(ans)