import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

import numpy as np
from functools import partial

fft_len = 1 << 18
fft = partial(np.fft.rfft, n=fft_len)
ifft = partial(np.fft.irfft, n=fft_len)

N,X,*A = map(int,read().split())

f = np.bincount(A)
Ff = fft(f)
g = np.rint(ifft(Ff ** 2)).astype(np.int64)

answer = 0 if X >= len(g) else g[X]
print(answer)