from collections import defaultdict mod = 998244353 U = 2 * 10 ** 5 + 10 class Combination: """ SIZEが10**6程度以下の二項係数を何回も呼び出したいときに使う 使い方: comb = Combination(SIZE, MOD) comb(10, 3) => 120 """ def __init__(self, N, MOD=10 ** 9 + 7): self.MOD = MOD self.__make_factorial_list(N) def __call__(self, n, k): if k < 0 or k > n: return 0 res = self.fact[n] * self.inv[k] % self.MOD res = res * self.inv[n - k] % self.MOD return res def nPk(self, n, k): if k < 0 or k > n: return 0 return self.fact[n] * self.inv[n - k] % self.MOD def nHk(self, n, k): if k == 0: return 1 return self.__call__(n + k - 1, k) def __make_factorial_list(self, N): self.fact = [1] * (N + 1) self.inv = [1] * (N + 1) MOD = self.MOD for i in range(1, N + 1): self.fact[i] = (self.fact[i - 1] * i) % MOD self.inv[N] = pow(self.fact[N], MOD - 2, MOD) for i in range(N, 0, -1): self.inv[i - 1] = (self.inv[i] * i) % MOD return comb = Combination(U, mod) fact = comb.fact inv = comb.inv N, X, Y = map(int, input().split()) M = max(0, X + Y - N) L = X - M R = Y - M ans = 0 for i in range(min(L, R) + 1): pair = comb(L, i) * comb.nPk(R, i) % mod ans = (ans + pair) % mod for i in range(N - X - Y): ans = ans * (N - i) % mod print(ans)