import scala.collection.mutable
import scala.io.Source.stdin

object Main extends App {

  val lines = stdin.getLines()
  val xs = {
    val nums = ('a' to 'z').map { (_, 0) }

    val m = mutable.Map(nums: _*)
    for {
      line <- lines
      c    <- line.map { _.toLower }
      if c.isLetter && c <= 'z'
    } {
      m(c) += 1
    }
    m.toSeq.sorted
  }

  for ((k, v) <- xs) {
    println(s"$k : $v")
  }
}

