- I met this problem as a subproblem many times and tried to find a solution for it but failed ,So I make an elegent statement for the problem asking for someone's help :↵
-[The problem is here ](/predownloaded/b2/d8/b2d822438819a8d48ef27c7945e3e1026180f088.png)↵
- [The example goes here](/predownloaded/94/0c/940ca4eeeb277b31b11b9bc8047e7bb69961a0ba![ ](https://codeforces.net/778eb3/prib.PNG)↵
- ![ ](/predownloaded/49/fe/49fef52a451bb3fda273a1a3816bd77a8cce755e.png)↵
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- [The example goes here](/predownloaded/94/0c/940ca4eeeb277b31b11b9bc8047e7bb69961a0ba
- ![ ](/predownloaded/49/fe/49fef52a451bb3fda273a1a3816bd77a8cce755e.png)↵
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