import sys from itertools import permutations from heapq import heappop,heappush from collections import deque import random import bisect input = lambda :sys.stdin.readline().rstrip() mi = lambda :map(int,input().split()) li = lambda :list(mi()) mod = 998244353 omega = pow(3,119,mod) rev_omega = pow(omega,mod-2,mod) N = 2*10**5 g1 = [1]*(N+1) # 元テーブル g2 = [1]*(N+1) #逆元テーブル inv = [1]*(N+1) #逆元テーブル計算用テーブル for i in range( 2, N + 1 ): g1[i]=( ( g1[i-1] * i ) % mod ) inv[i]=( ( -inv[mod % i] * (mod//i) ) % mod ) g2[i]=( (g2[i-1] * inv[i]) % mod ) inv[0]=0 def _ntt(f,L,reverse=False): F=[f[i] for i in range(L)] n = L.bit_length() - 1 base = omega if reverse: base = rev_omega if not n: return F size = 2**n wj = pow(base,2**22,mod) res = [0]*2**n for i in range(n,0,-1): use_omega = pow(base,2**(22+i-n),mod) res = [0]*2**n size //= 2 w = 1 for j in range(0,L//2,size): for a in range(size): res[a+j] = (F[a+2*j] + w * F[a+size+2*j]) % mod t = (w * wj) % mod res[L//2+a+j] = (F[a+2*j] + t * F[a+size+2*j]) % mod w = (w * use_omega) % mod F = res return res def ntt(f,L=0): l = len(f) if not L: L = 1<<((l-1).bit_length()) while len(f) c[i] = sum(a[j] * b[i - j] for j in range(i + 1)) % 998244353. It returns an empty list if at least one of a and b are empty. Constraints ----------- > len(a) + len(b) <= 8388609 Complexity ---------- > O(n log n), where n = len(a) + len(b). """ n = len(a) m = len(b) if n == 0 or m == 0: return [] if min(n, m) <= 0: return _convolution_naive(a, b) if a is b: return _convolution_square(a) return _convolution_fft(a, b) def inverse(f,limit): assert(f[0]!=0) f += [0] * (limit-len(f)) l = len(f) L = 1<<((l-1).bit_length()) n = L.bit_length()-1 f = f[:L] f+=[0]*(L-len(f)) res = [pow(f[0],mod-2,mod)] for i in range(1,n+1): h = convolution(res,f[:2**i])[:2**i] h = [(-h[i]) % mod for i in range(2**i)] h[0] = (h[0]+2) % mod res = convolution(res,h)[:2**i] return res[:limit] N,M = mi() f = [0] * (N+1) f[1] = 1 for n in range(2,N+1): f[n] = f[n-1] - f[n-2] f[n] %= mod K = min(N,M) M %= mod f = [-f[i]*(M-i+1) % mod for i in range(K+1)] f[0] = 1 inv_f = inverse(f,N+1) print(inv_f[N])