MOD = 998244353

def main():
    import sys
    N, B, W = map(int, sys.stdin.readline().split())
    
    if W != N - 3 * B:
        print(0)
        return
    
    if N < 3 * B:
        print(0)
        return
    
    # Compute C(n, k) mod MOD where n = N - 2B, k = B
    n = N - 2 * B
    k = B
    
    if k < 0 or k > n:
        print(0)
        return
    
    # Precompute factorial and inverse factorial modulo MOD up to n
    max_n = n
    fact = [1] * (max_n + 1)
    for i in range(1, max_n + 1):
        fact[i] = fact[i-1] * i % MOD
    
    inv_fact = [1] * (max_n + 1)
    inv_fact[max_n] = pow(fact[max_n], MOD-2, MOD)
    for i in range(max_n-1, -1, -1):
        inv_fact[i] = inv_fact[i+1] * (i+1) % MOD
    
    # Compute combination
    comb = fact[n] * inv_fact[k] % MOD
    comb = comb * inv_fact[n - k] % MOD
    print(comb)

if __name__ == "__main__":
    main()