import sys input = lambda :sys.stdin.readline()[:-1] ni = lambda :int(input()) na = lambda :list(map(int,input().split())) yes = lambda :print("yes");Yes = lambda :print("Yes");YES = lambda : print("YES") no = lambda :print("no");No = lambda :print("No");NO = lambda : print("NO") ####################################################################### n,a,b = na() mod = 998244353 nn = n + 10 fact = [1] * nn for i in range(nn - 1): fact[i + 1] = fact[i] * (i + 1) % mod invfact = [1] * nn invfact[nn - 1] = pow(fact[nn - 1], mod - 2, mod) for i in range(nn - 1)[::-1]: invfact[i] = invfact[i + 1] * (i + 1) % mod def binom(x, y): if x < 0 or y < 0 or x - y < 0: return 0 return fact[x] * invfact[y] % mod * invfact[x - y] % mod if a != b: print((fact[n] - 2 * fact[n-1] + fact[n-2])%mod) else: print((fact[n] - 2 * fact[n-1])%mod)