MOD = 998244353

N, K = map(int, input().split())

result = 0

for x in range(1, K + 1):
    a = pow(x, N-1, MOD)
    b = pow(x-1, N-1, MOD)
    c = a * x % MOD
    d = b * (x-1) % MOD
    
    # Compute term1: (K - x) * N * (a - b)
    term1_part = ((K - x) % MOD) * (N % MOD) % MOD
    diff_ab = (a - b) % MOD
    term1 = term1_part * diff_ab % MOD
    
    # Compute term2: (c - d) - N * b
    term2_part = (c - d) % MOD
    term2_part = (term2_part - (N % MOD) * b) % MOD
    term2 = term2_part
    
    total = (term1 + term2) % MOD
    total = total * x % MOD
    
    result = (result + total) % MOD

print(result)