MOD = 998244353

n, a, b = map(int, input().split())
if n == 2:
  if a == b:
    print("0")
  else:
    print("1")
  exit()

fact = [1 for _ in range(n + 1)]
for x in range(2, n + 1):
  fact[x] = (fact[x - 1] * x) % MOD

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