CF527B.Error Correct System

普及/提高-

通过率:0%

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题目描述

Ford Prefect got a job as a web developer for a small company that makes towels. His current work task is to create a search engine for the website of the company. During the development process, he needs to write a subroutine for comparing strings SS and TT of equal length to be "similar". After a brief search on the Internet, he learned about the Hamming distance between two strings SS and TT of the same length, which is defined as the number of positions in which SS and TT have different characters. For example, the Hamming distance between words "permanent" and "pergament" is two, as these words differ in the fourth and sixth letters.

Moreover, as he was searching for information, he also noticed that modern search engines have powerful mechanisms to correct errors in the request to improve the quality of search. Ford doesn't know much about human beings, so he assumed that the most common mistake in a request is swapping two arbitrary letters of the string (not necessarily adjacent). Now he wants to write a function that determines which two letters should be swapped in string SS , so that the Hamming distance between a new string SS and string TT would be as small as possible, or otherwise, determine that such a replacement cannot reduce the distance between the strings.

Help him do this!

输入格式

The first line contains integer nn ( 1<=n<=2000001<=n<=200000 ) — the length of strings SS and TT .

The second line contains string SS .

The third line contains string TT .

Each of the lines only contains lowercase Latin letters.

输出格式

In the first line, print number xx — the minimum possible Hamming distance between strings SS and TT if you swap at most one pair of letters in SS .

In the second line, either print the indexes ii and jj ( 1<=i,j<=n1<=i,j<=n , iji≠j ), if reaching the minimum possible distance is possible by swapping letters on positions ii and jj , or print "-1 -1", if it is not necessary to swap characters.

If there are multiple possible answers, print any of them.

输入输出样例

  • 输入#1

    9
    pergament
    permanent
    

    输出#1

    1
    4 6
    
  • 输入#2

    6
    wookie
    cookie
    

    输出#2

    1
    -1 -1
    
  • 输入#3

    4
    petr
    egor
    

    输出#3

    2
    1 2
    
  • 输入#4

    6
    double
    bundle
    

    输出#4

    2
    4 1
    

说明/提示

In the second test it is acceptable to print i=2i=2 , j=3j=3 .

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