# 包除原理だな

mod = 998244353
N, A, B = map(int, input().split())

if A != B:
    total = 1
    for i in range(1, N+1):
        total *= i
        total %= mod
    deduct1 = 1
    for i in range(1, N):
        deduct1 *= i
        deduct1 %= mod
    add1 = 1
    for i in range(1, N-1):
        add1 *= i
        add1 %= mod    
    ans = (total - deduct1*2 + add1)%mod
    #print(total, deduct1, add1)
    print(ans)
elif A == B:
    total = 1
    for i in range(1, N+1):
        total *= i
        total %= mod
    deduct1 = 1
    for i in range(1, N):
        deduct1 *= i
        deduct1 %= mod
    add1 = 0
    ans = (total - deduct1*2 + add1)%mod
    #print(total, deduct1, add1)
    print(ans)