import sys
from collections import deque, Counter
input = lambda: sys.stdin.readline().rstrip()
ii = lambda: int(input())
mi = lambda: map(int, input().split())
li = lambda: list(mi())
inf = 2 ** 63 - 1
mod = 998244353

n, a, b = mi()

fact = [1] * (n + 1)

for i in range(1, n + 1):
    fact[i] = fact[i - 1] * i
    fact[i] %= mod

if a == b:
    ans = (fact[n] - 2 * fact[n - 1]) % mod
else:
    ans = (fact[n] - 2 * fact[n - 1] + fact[n - 2]) % mod

print(ans)