import sys
input = sys.stdin.readline
MOD = 998244353
N, K = map(int, input().split())
L = 10**8
dp = [
    1,
    808258749,
    117153405,
    761699708,
    573994984,
    62402409,
    511621808,
    242726978,
    887890124,
    875880304,
]
K = min(K, N-K)
if N-K>=MOD:
    bunsi = 1
    for i in range(N-K+1, N+1):
        bunsi = bunsi * i % MOD
    bunbo = 1
    for i in range(1, K+1):
        bunbo = bunbo * i % MOD
    ans = bunsi * pow(bunbo, MOD-2, MOD) % MOD
    print(ans)
    exit()

cnt = N//L
bunsi = dp[cnt]
for i in range(cnt*L+1, N+1):
    bunsi = bunsi * i % MOD
cnt = K//L
bunbo = dp[cnt]
for i in range(cnt*L+1, K+1):
    bunbo = bunbo * i % MOD
cnt = (N-K)//L
bunbo = bunbo * dp[cnt] % MOD
for i in range(cnt*L+1, (N-K)+1):
    bunbo = bunbo * i % MOD
ans = bunsi * pow(bunbo, MOD-2, MOD) % MOD
print(ans)