mod=998244353
N,K=map(int, input().split())
def xgcd(a, b):
    x0, y0, x1, y1 = 1, 0, 0, 1
    while b != 0:
        q, a, b = a // b, b, a % b
        x0, x1 = x1, x0 - q * x1
        y0, y1 = y1, y0 - q * y1
    return a, x0, y0

def modinv(a, m):
    g, x, y = xgcd(a, m)
    if g != 1:
        raise Exception('modular inverse does not exist')
    else:
        return x % m
        
def f(x,y):
  return x*10000+y
def ff(z):
  x,y=z//10000,z%10000
  return x,y
  
gt=modinv(N,mod)
from collections import deque
d=deque()
d.append((0,0))
dp=[[0]*(N+1) for i in range(K//2+1)]
V=[[-1]*(N+1) for i in range(K//2+1)]
dp[0][0]=1;V[0][0]=0
for i in range(K):
  nd=deque();DD={}
  while d:
    r,y=d.popleft()
    p=N-y
    c=dp[r][y]
    if y!=0:
      a=(y*gt*c)%mod
      if V[r+1][y-1]==-1:
        V[r+1][y-1]=i+1
        nd.append((r+1,y-1))
      dp[r+1][y-1]+=a
      dp[r+1][y-1]%=mod 
    if p!=0:
      a=(p*gt*c)%mod
      if V[r][y+1]==-1:
        V[r][y+1]=i+1
        nd.append((r,y+1))
      dp[r][y+1]+=a
      dp[r][y+1]%=mod
  d=nd 
  D=DD
  
ans=0
for r in range(K//2+1):
  for y in range(N+1):
    if V[r][y]==K:
      p=N-y
      c=r+y+p
      ans+=c*dp[r][y]
      ans%=mod
print(ans)