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

MOD = 998244353
factorial_li_mod = [1]
for i in range(1,N+1):
    factorial_li_mod.append((factorial_li_mod[-1]*i)%MOD)

ans = factorial_li_mod[N]-factorial_li_mod[N-1]*2
if A != B:
    ans += factorial_li_mod[N-2]
print(ans%MOD)