from collections import defaultdict
n, p = map(int, input().split())
a = list(map(int, input().split()))
x = p
res = 0
while max(a) > x:
    d = defaultdict(int)
    for i in range(n):
        d[a[i] % x] += 1
    for v in d.values():
        res += v*(v-1)//2
    x *= p
print(res)