MOD = 998244353

N, A, B = map(int, input().split())

max_n = N
fact = [1] * (max_n + 1)
for i in range(1, max_n + 1):
    fact[i] = fact[i-1] * i % MOD

if A != B:
    term = (2 * fact[N-1] - fact[N-2]) % MOD
else:
    term = (2 * fact[N-1]) % MOD

ans = (fact[N] - term) % MOD
ans = (ans + MOD) % MOD  # Ensure non-negative

print(ans)