def nPr(n, r, mod):
    if ( r<0 or r>n ):
        return 0
    return g1[n] * g2[n-r] % mod

def nCr(n, r, mod):
    if ( r<0 or r>n ):
        return 0
    r = min(r, n-r)
    return (g1[n] * g2[r] % mod) * g2[n-r] % mod

MOD = 998244353
N, A, B = map(int, input().split())

g1 = [1, 1] # 元テーブル
g2 = [1, 1] #逆元テーブル
inverse = [0, 1] #逆元テーブル計算用テーブル
fact = [1, 1]

for i in range( 2, N + 1 ):
    g1.append( ( g1[-1] * i ) % MOD )
    inverse.append( ( -inverse[MOD % i] * (MOD//i) ) % MOD )
    g2.append( (g2[-1] * inverse[-1]) % MOD )
    fact.append( (fact[-1] * i) % MOD )

all = nPr(N, N, MOD)
if A==B:
    ng = nPr(N-1, N-1, MOD) + nPr(N-1, N-1, MOD)
else:
    ng = nPr(N-1, N-1, MOD) + nPr(N-1, N-1, MOD) - nPr(N-2, N-2, MOD)
print((all-ng)%MOD)