from collections import deque MOD = 998244353 class FFT: def __init__(self, MOD=998244353): FFT.MOD = MOD g = self.primitive_root_constexpr() ig = pow(g, FFT.MOD - 2, FFT.MOD) FFT.W = [pow(g, (FFT.MOD - 1) >> i, FFT.MOD) for i in range(30)] FFT.iW = [pow(ig, (FFT.MOD - 1) >> i, FFT.MOD) for i in range(30)] def primitive_root_constexpr(self): if FFT.MOD == 998244353: return 3 elif FFT.MOD == 200003: return 2 elif FFT.MOD == 167772161: return 3 elif FFT.MOD == 469762049: return 3 elif FFT.MOD == 754974721: return 11 divs = [0] * 20 divs[0] = 2 cnt = 1 x = (FFT.MOD - 1) // 2 while x % 2 == 0: x //= 2 i = 3 while i * i <= x: if x % i == 0: divs[cnt] = i cnt += 1 while x % i == 0: x //= i i += 2 if x > 1: divs[cnt] = x cnt += 1 g = 2 while 1: ok = True for i in range(cnt): if pow(g, (FFT.MOD - 1) // divs[i], FFT.MOD) == 1: ok = False break if ok: return g g += 1 def fft(self, k, f): for l in range(k, 0, -1): d = 1 << l - 1 U = [1] for i in range(d): U.append(U[-1] * FFT.W[l] % FFT.MOD) for i in range(1 << k - l): for j in range(d): s = i * 2 * d + j f[s], f[s + d] = (f[s] + f[s + d]) % FFT.MOD, U[j] * (f[s] - f[s + d]) % FFT.MOD def ifft(self, k, f): for l in range(1, k + 1): d = 1 << l - 1 for i in range(1 << k - l): u = 1 for j in range(i * 2 * d, (i * 2 + 1) * d): f[j+d] *= u f[j], f[j + d] = (f[j] + f[j + d]) % FFT.MOD, (f[j] - f[j + d]) % FFT.MOD u = u * FFT.iW[l] % FFT.MOD def convolve(self, A, B): n0 = len(A) + len(B) - 1 k = (n0).bit_length() n = 1 << k A += [0] * (n - len(A)) B += [0] * (n - len(B)) self.fft(k, A) self.fft(k, B) A = [a * b % FFT.MOD for a, b in zip(A, B)] self.ifft(k, A) inv = pow(n, FFT.MOD - 2, FFT.MOD) A = [a * inv % FFT.MOD for a in A] del A[n0:] return A n, K = map(int, input().split()) A = list(map(int, input().split())) cnt = {} for a in A: cnt[a] = cnt.get(a, 0) + 1 queue = deque() tot = 0 for k in sorted(set(A)): v = cnt[k] dp = [[0] * (tot + 1)] dp[0][0] = 1 l = 1 for _ in range(v): ndp = [[0] * (tot + 1) for _ in range(l + tot)] for i in range(l): for j in range(tot + 1): ndp[i + j][j] += dp[i][j] ndp[i + j][j] %= MOD l += tot for i in range(1, l): for j in range(1, tot + 1): ndp[i][j] += ndp[i - 1][j - 1] ndp[i][j] %= MOD dp = ndp tot += v poly = [sum(ndp[i]) for i in range(l)] del poly[K+1:] queue.append(poly) fft = FFT() while len(queue) > 1: A = queue.popleft() B = queue.popleft() C = fft.convolve(A, B) del C[K+1:] queue.append(C) A = queue[0] if len(A) <= K: print(0) else: print(A[K])