There are lot of interesting problems in gym. But there are no editorial for them (maybe codeforces has better reason for that). So it is very difficult to upsolve them as i don't have any hints ,can't see others solution or even can't see the test case where i am wrong. The only way to get hints is to knock somebody who has solved it. But sometimes it is time consuming as it depends on availability of other person. So upsolving is very hard for gym contests. What we should do in this situation?
Sorry for my bad English.