M=998244353
L=10**8
p=[1,808258749,117153405,761699708,573994984,62402409,511621808,242726978,887890124,875880304,0]

def f(x):
  a=p[x//L]
  for i in range((x//L)*L+1,x+1):
    a*=i
    a%=M
  return a

n,k=map(int,input().split())
k=min(k,n-k)

if k<=1755647:
  a=1
  for i in range(k):
    a*=(n-i)*pow(i+1,M-2,M)
    a%=M
  print(a)
  exit()

print(f(n)*pow(f(k)*f(n-k),M-2,M)%M)