n,a,b=map(int,input().split())
mod=998244353
#all-(a~)-(~b)+(a~b)
ans=1
for i in range(1,n+1):
  ans*=i
  ans%=mod
  
A=1
for i in range(1,n):
  A*=i
  A%=mod
  
AB=1
for i in range(1,n-1):
  AB*=i
  AB%=mod
  
if a==b:
  ans-=2*A
  ans%=mod
else:
  ans-=2*A
  ans+=AB
  ans%=mod
print(ans)