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

mod = 998244353
inv = [1] * (N + 1)
for i in range(2, N + 1):
    inv[i] = mod - mod // i * inv[mod % i] % mod

ans = 0
c = 1
for i in range(N):
    ans += c * pow(i, K, mod)
    c = c * (N - i - 1) * inv[i + 1] % mod
ans %= mod
print(ans)