from collections import *
from itertools import *
from heapq import *
from functools import *
import sys,math
input = sys.stdin.readline

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

X = [1]*(N+1)
for i in range(1,N+1):
    X[i] = i*X[i-1]
    X[i] %= mod
if A!=B:
    ans = (X[N] - 2*X[N-1] + X[N-2])%mod
else:
    ans = (X[N] - 2*X[N-1])%mod
print(ans)