MOD = 998_244_353

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

    fact = [1]

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

    ans = (fact[N] - fact[N - 1] * 2) % MOD
    
    if A != B:
        ans += fact[N - 2]
    
    ans += MOD
    ans %= MOD
    print(ans)
    return 0

main()