import java.util.Scanner

object Main {
  def main(args: Array[String]) {
    val sc = new Scanner(System.in)
    val x1, y1, x2, y2, x3, y3 = sc.nextInt()

    var xs = Array((-x1, y1, 0), (-x2, y2, 1), (-x3, y3, 2))
    for (x <- xs.sorted.map(_._3))
      println((x + 'A').toChar)
  }
}