#agc060c. [agc060_c]Large Heap

[agc060_c]Large Heap

Problem Statement

Consider a permutation P=(P1,P2,cdots,P2N1)P=(P_1,P_2,\\cdots,P_{2^N-1}) of (1,2,cdots,2N1)(1,2,\\cdots,2^N-1). PP is said to be heaplike if and only if all of the following conditions are satisfied.

  • Pi<P2iP_i < P_{2i} (1leqileq2N111 \\leq i \\leq 2^{N-1}-1)
  • Pi<P2i+1P_i < P_{2i+1} (1leqileq2N111 \\leq i \\leq 2^{N-1}-1)

You are given integers AA and BB. Let U=2AU=2^A and V=2B+11V=2^{B+1}-1.

Find the probability, modulo 998244353998244353, that PU<PVP_U<P_V for a heaplike permutation chosen uniformly at random.

Definition of probability modulo 998244353998244353

It can be proved that the sought probability is always rational. Additionally, under the constraints of this problem, when the sought rational number is represented as an irreducible fraction fracPQ\\frac{P}{Q}, it can be proved that Qneq0pmod998244353Q \\neq 0 \\pmod{998244353}. Therefore, there is a unique integer RR such that RtimesQequivPpmod998244353R \\times Q \\equiv P \\pmod{998244353} and 0leqRlt9982443530 \\leq R \\lt 998244353. Print this RR.

Constraints

  • 2leqNleq50002 \\leq N \\leq 5000
  • 1leqA,BleqN11 \\leq A,B \\leq N-1
  • All numbers in the input are integers.

Input

The input is given from Standard Input in the following format:

NN AA BB

Output

Print the answer.


Sample Input 1

2 1 1

Sample Output 1

499122177

There are two heaplike permutations: P=(1,2,3),(1,3,2)P=(1,2,3),(1,3,2). The probability that P2<P3P_2<P_3 is 1/21/2.


Sample Input 2

3 1 2

Sample Output 2

124780545

Sample Input 3

4 3 2

Sample Output 3

260479386

Sample Input 4

2022 12 25

Sample Output 4

741532295