n,a,b = map(int,input().split())
mod = 998244353

facts = [1]*(n+1)
for i in range(2,n+1):
    facts[i] = facts[i-1]*i%mod


ans = facts[n]-2*facts[n-1]
if a != b:
    ans += facts[n-2]
ans %= mod
print(ans)