CF1866M.Mighty Rock Tower

普及/提高-

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题目描述

Pak Chanek comes up with an idea in the midst of boredom to play a game. The game is a rock tower game. There is a big rock that is used as a base. There are also NN small identical rocks that Pak Chanek will use to build a rock tower with a height of NN above the base rock.

Initially, there are no small rocks that are located above the base rock. In other words, the height of the tower above the base rock is initially 00 . In one move, Pak Chanek can place one small rock onto the top of the tower which makes the height of the tower above the base rock increase by 11 . Each time Pak Chanek place one small rock, the following will happen after the small rock is placed:

  • Let's say xx is the height of the tower above the base rock right after the small rock is placed.
  • There is a probability of PxP_x percent that the topmost rock falls.
  • If x2x \geq 2 and the topmost rock falls, then there is another probability of PxP_x percent that the 22 -nd topmost rock also falls.
  • If x3x \geq 3 and the 22 -nd topmost rock falls, then there is another probability of PxP_x percent that the 33 -rd topmost rock also falls.
  • If x4x \geq 4 and the 33 -rd topmost rock falls, then there is another probability of PxP_x percent that the 44 -th topmost rock also falls.
  • And so on.

If the tower successfully reaches a height of NN without any rocks falling after that, then the game is ended.

If given an integer array [P1,P2,,PN][P_1, P_2, \ldots, P_N] , what is the expected value of the number of moves that Pak Chanek needs to do to end the game? It can be proven that the expected value can be represented as an simple fraction PQ\frac{P}{Q} where QQ is coprime to 998244353998\,244\,353 . Output the value of P×Q1P \times Q^{-1} modulo 998244353998\,244\,353 .

输入格式

The first line contains a single integer NN ( 1N21051 \leq N \leq 2\cdot10^5 ) — the required height of the rock tower.

The second line contains NN integers P1,P2,P3,,PNP_1, P_2, P_3, \ldots, P_N ( 0Pi990 \leq P_i \leq 99 ).

输出格式

An integer representing the expected value of the number of moves that Pak Chanek needs to do to end the game, modulo 998244353998\,244\,353 .

输入输出样例

  • 输入#1

    2
    80 50

    输出#1

    499122186
  • 输入#2

    3
    25 16 20

    输出#2

    879786027

说明/提示

In the first example, the expected value of the number of moves that Pak Chanek needs to do to end the game is 192\frac{19}{2} .

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