import org.jetbrains.kotlinx.dataframe.*
import org.jetbrains.kotlinx.dataframe.annotations.*
import org.jetbrains.kotlinx.dataframe.api.*
import org.jetbrains.kotlinx.dataframe.io.*

fun box(): String {
    val df = dataFrameOf("a")(123).convert { a }.perRowCol { row, col -> "" }
    val value: String = df.a[0]
    return "OK"
}