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

ans = 1
mod = 998244353
for i in range(n):
    ans *= (i+1)
    ans %= mod

sub1 = 1
for i in range(n-1):
    sub1 *= i+1
    sub1 %= mod

sub2 = 1
for i in range(n-2):
    sub2 *= i+1
    sub2 %= mod

if a != b:
    print((ans- 2*sub1 + sub2)%mod)
else:
    print((ans - 2*sub1)%mod)