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

bunshi = 1
for i in range(K):
    bunshi *= N-i
    bunshi %= MOD

bunbo = 1
for i in range(1,K+1):
    bunbo *= i
    bunbo %= MOD

print(bunshi * pow(bunbo,-1,MOD) % MOD)