- 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 ](https://mirror.codeforces.com/3c3a27/exmp.PNG/predownloaded/94/0c/940ca4eeeb277b31b11b9bc8047e7bb69961a0ba.png)↵
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- [The problem is here ](/predownloaded/b2/d8/b2d822438819a8d48ef27c7945e3e1026180f088.png)↵
- [The example goes here
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