import numpy as np

N,M = map(int,input().split())
MOD = 998244353

if N > M or N == 1:
    print(1)
    exit(0)

dp = np.zeros((M + 1), dtype='i')
dp[0] = 1

for i in range(M):
    j = i + N
    if j <= M:
        dp[j] += dp[i]
        dp[j] %= MOD
    dp[i + 1] += dp[i]
    dp[i + 1] %= MOD

print(dp[-1])