CF803E.Roma and Poker

普及/提高-

通过率:0%

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题目描述

Each evening Roma plays online poker on his favourite website. The rules of poker on this website are a bit strange: there are always two players in a hand, there are no bets, and the winner takes 11 virtual bourle from the loser.

Last evening Roma started to play poker. He decided to spend no more than kk virtual bourles — he will stop immediately if the number of his loses exceeds the number of his wins by kk . Also Roma will leave the game if he wins enough money for the evening, i.e. if the number of wins exceeds the number of loses by kk .

Next morning Roma found a piece of paper with a sequence on it representing his results. Roma doesn't remember the results exactly, and some characters in the sequence are written in a way such that it's impossible to recognize this character, so Roma can't recall whether he won kk bourles or he lost.

The sequence written by Roma is a string ss consisting of characters W (Roma won the corresponding hand), L (Roma lost), D (draw) and ? (unknown result). Roma wants to restore any valid sequence by changing all ? characters to W, L or D. The sequence is called valid if all these conditions are met:

  • In the end the absolute difference between the number of wins and loses is equal to kk ;
  • There is no hand such that the absolute difference before this hand was equal to kk .

Help Roma to restore any such sequence.

输入格式

The first line contains two numbers nn (the length of Roma's sequence) and kk ( 1<=n,k<=10001<=n,k<=1000 ).

The second line contains the sequence ss consisting of characters W, L, D and ?. There are exactly nn characters in this sequence.

输出格式

If there is no valid sequence that can be obtained from ss by replacing all ? characters by W, L or D, print NO.

Otherwise print this sequence. If there are multiple answers, print any of them.

输入输出样例

  • 输入#1

    3 2
    L??
    

    输出#1

    LDL
    
  • 输入#2

    3 1
    W??
    

    输出#2

    NO
    
  • 输入#3

    20 5
    ?LLLLLWWWWW?????????
    

    输出#3

    WLLLLLWWWWWWWWLWLWDW
    
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