The language of the round is Kotlin. Kotlin is a statically-typed programming language that runs on the Java Virtual Machine and also can be compiled to JavaScript source code. Its primary development is from a team of JetBrains programmers based in Saint Petersburg, Russia (the name comes from the Kotlin Island, near St. Petersburg).

Here is an example of the simplest program on Kotlin to print sum of two numbers:

fun main(args: Array<String>) {
    val (x, y) = readLine()!!.split(' ').map(String::toInt)
    println(x + y)
}

Here are some links to help you with Kotlin:

• https://en.wikipedia.org/wiki/Kotlin_(programming_language)
• https://kotlinlang.org/docs/reference/
• http://try.kotlinlang.org/ — be careful: reading from the console in the web-IDE is not allowed
• and Google!

You can download standalone compiler (version 1.0.1) by the link http://s.codeforces.com/files/kotlin-compiler-1.0.1.zip Also you need JRE (virtual Java machine), you can find it by the link http://www.oracle.com/technetwork/java/javase/downloads/jre8-downloads-2133155.html

The password from the archives with IDEA (IDE supporting Kotlin out of the box): c8bf9dd9b91ad9ff Links to IDEA are below or you can download it from the official website

Good luck!

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UPD: You can predownload development pack (sorry, 300MB). In fact, you can take part without it — the Custom Invocation tab will be available during the contest. Also we will publish more compact tools 30 minutes before the start.

All archives are encrypted. The password will be announced 30 minutes before the contest.

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Surprise Language Round #8 will start on June 16, 16:00 (UTC). It will be unusual entertaining contest. Solutions on the only programming language will be allowed.

Thus, it is expected that during the round, participants can get acquainted with the language and solve a few simple problems. The language will be announced 30 minutes before the start of the round. At the same time (or earlier but encrypted archives) we will publish the archives with the tools to write programs in this language.

I am pleased to announce that the top 20 participants will receive an exclusive t-shirt, and another 10 random participants among those who solved at least three problems will receive an exclusive t-shirt too.

The rules of the contest are as follows:

• The contest is unrated for everybody.
• The round uses ACM ICPC rules: the standing is defined by the number of solved problems, ties are resolved based on penalty time. Initially the penalty is 0, and for each solved problem it is increased by submission time (since the start of the contest) + 20 minutes for each failed submission. The solution is considered to be correct if it passes all tests from a predefined test set; you know whether the solution is right immediately after sending it. There are no hacks.
• The round will have 8-10 problems, sorted by estimated complexity, and you have 2 hours to solve it.
• Solutions are accepted only in one language, which will be announced in 30 minutes before the contest.
• Please reread this post at the beginning of the contest: we will announce the language and add instructions to install the compiler (the contest interface will provide an option to run your solutions online as well) and links to useful manuals. Other than that, learning the language is up to the competitor. You can use any resources to solve the problems (as long as you remember that this is an individual competition); you don't have to limit yourself to the manuals provided in the post.

Good luck!