n,a,b=map(int,input().split())
mod=998244353
s = 1
for i in range(n,0,-1):
    s=(s*i)%mod
    
if a != b:
    u=1
    for i in range(n-1,0,-1):
        u=(u*i)%mod
    su=1
    for i in range(n-2,0,-1):
        su=(su*i)%mod
    
    print((s-u-u+su)%mod)
    
else:
    u=1
    for i in range(n-1,0,-1):
        u=(u*i)%mod
    
    print((s-u-u)%mod)