from math import sqrt mod = 998244353 N, M = map(int, input().split()) sq = int(sqrt(M) + 3) dp = [[0] * (M + 1) for _ in range(sq)] nx = [[0] * (M + 1) for _ in range(sq)] dp[0][0] = 1 for _ in range(N): for i in range(sq): for j in range(M + 1): nx[i][j] = 0 for i in range(sq): for j in range(M + 1): if dp[i][j] == 0: continue im1 = abs(i - 1) if j + im1 <= M: nx[im1][j + im1] += dp[i][j] if j + i <= M: nx[i][j + i] += dp[i][j] * 2 if i != sq - 1 and j + i + 1 <= M: nx[i + 1][j + i + 1] += dp[i][j] dp, nx = nx, dp for i in range(sq): for j in range(M + 1): dp[i][j] %= mod print(dp[0][M])