mod=998244353
def modpow(a,b,m):
  res=1
  while b:
    if b%2:
      res*=a
      res%=m
    a*=a
    a%=m
    b//=2
  return res
def prodmat(a,b):
  x,y,z=len(a),len(b[0]),len(b)
  c=[[0 for i in range(y)] for j in range(x)]
  for i in range(x):
    for j in range(y):
      for k in range(z):
        c[i][k]+=a[i][j]*b[j][k]
        c[i][k]%=mod
  return c
def powermat(a,k):
  x=len(a)
  b=[[0 for i in range(x)] for j in range(x)]
  for i in range(x):
    b[i][i]=1
  while k:
    if k%2:
      b=prodmat(b,a)
    a=prodmat(a,a)
    k//=2
  return b
n,q=map(int,input().split())
ans=0
for i in range(1,n):
  x=i*(n-i+1)
  y=n*(n+1)//2-x
  z=(n-i)*(n-i+1)*(n-i+2)//6
  x%=mod
  y%=mod
  z%=mod
  a=[[0 for i in range(3)] for j in range(3)]
  a[1][2]+=z
  a[2][2]+=n*(n+1)%mod
  a[0][0]+=y
  a[0][0]+=n*(n+1)//2%mod
  a[1][1]+=y
  a[1][1]+=n*(n+1)//2%mod
  a[1][0]+=x
  a[0][1]+=x
  a=powermat(a,q)
  ans+=a[0][2]
print(ans*modpow(2,mod-2,mod)%mod)