n, a, b = map(int, input().split())
mod = 998244353
fac = [1]
for i in range(n):
  fac.append(fac[i]*(i+1)%mod)
if a != b:
  ans = fac[n] - fac[n-1] * 2 + fac[n-2]
else:
  ans = (n - 2) * fac[n-1]
ans %= mod
print(ans)