mod = 998244353

n, m = map(int, input().split())
A = m + 2 * n
B = 2 * n + 1

if B > A:
    print(0)
else:
    a_mod = A % mod
    # Compute numerator: product of (a_mod - k) mod mod for k from 0 to B-1
    numerator = 1
    for k in range(B):
        term = (a_mod - k) % mod
        numerator = (numerator * term) % mod
    
    # Compute B! mod mod
    factorial = 1
    for i in range(1, B + 1):
        factorial = (factorial * i) % mod
    
    # Compute inverse of B! using Fermat's little theorem
    inv_factorial = pow(factorial, mod - 2, mod)
    
    # Calculate combination and final answer
    combination = (numerator * inv_factorial) % mod
    ans = (n * combination) % mod
    print(ans)