N,A,B = map(int,input().split())
P = [1]
mod = 998244353
for i in range(1,N+1):
    P.append(P[-1]*i%mod)
if A==B:
    print(P[N]-P[N-1]*2)
else:
    print((P[N]-P[N-1]*2+P[N-2])%mod)