""" Tea Time (5) 想定解 定数倍高速化Ver 注: O(N+K^3) なので、通りません """ import sys from sys import stdin mod = 998244353 def modfac(n, MOD): f = 1 factorials = [1] for m in range(1, n + 1): f *= m f %= MOD factorials.append(f) inv = pow(f, MOD - 2, MOD) invs = [1] * (n + 1) invs[n] = inv for m in range(n, 1, -1): inv *= m inv %= MOD invs[m - 1] = inv return factorials, invs def modnCr(n,r): if n < 0 or r < 0 or n < r: return 0 return fac[n] * inv[n-r] * inv[r] % mod fac,inv = modfac(1000,mod) N,K = map(int,stdin.readline().split()) # 制約チェック assert 1 <= N <= 400 assert 0 <= K <= 400 if K == 0: print (1) sys.exit() # 1つ目の括弧は置いた状態から開始 dp = [[[0],[0]] for l in range(2)] dp[0][1][0] = 1 #last,s,p の順番 for i in range(2,2*K+1): ndp = [[[0] * i for nnum in range(min(K+1,i+1))] for l in range(2)] for put in range(2): #置く括弧 0 = ( , 1 = ) for last in range(2): put_neq_last = (1 if last != put else 0) for ls in range(len(dp[0])): news = ls + (1,-1)[put] if 0 <= news < len(ndp[0]): for lp in range(len(dp[0][0])): newp = lp + put_neq_last ndp[put][news][newp] = (ndp[put][news][newp] + dp[last][ls][lp]) % mod dp = ndp #print (dp) ans = 0 for p in range(len(dp[0][0])): now = dp[1][0][p] * modnCr(2*K+N-p,N-p) #print (p,dp[0][p][1] , modnCr(2*K+N-p,N-p)) ans += now ans %= mod print (ans)