mod=998244353
def cmb(n,r):
  if r<0 or r>n:
    return 0
  return ((g1[n]*g2[r]%mod)*g2[n-r])%mod
 
N=300000
g1=[1]*(N+3)
for i in range(2,N+3):
  g1[i]=g1[i-1]*i%mod
g2=[0]*len(g1)
g2[-1]=pow(g1[-1],mod-2,mod)
for i in range(N+1,-1,-1):
  g2[i]=g2[i+1]*(i+1)%mod
inv=[0]*(N+3)
for i in range(1,N+3):
  inv[i]=g2[i]*g1[i-1]%mod

N=int(input())
M=int(input())
ANS=pow(2,N,mod)
N%=mod
for i in range(M):
  ANS-=cmb(N,i)
print(ANS%mod)