import sys
input = sys.stdin.readline


def main():
    N, A, B = map(int, input().split())
    MOD = 998244353
    ans = fact(N) - 2 * fact(N - 1) % MOD
    if A != B:
        ans += fact(N - 2)
        ans %= MOD
    print(ans)


def fact(n, mod=998244353):
    ret = 1
    for i in range(2, n + 1):
        ret *= i
        ret %= mod
    return ret


main()