import java.util.Scanner import scala.collection.Searching._ import scala.annotation.tailrec import scala.collection.immutable.Queue import scala.collection.mutable import scala.io.StdIn.readLine class IUnionFind(val size: Int) { private case class Node(var parent: Option[Int], var treeSize: Int) private val nodes = Array.fill[Node](size)(new Node(None, 1)) def union(t1: Int, t2: Int): IUnionFind = { if (t1 == t2) return this val root1 = root(t1) val root2 = root(t2) if (root1 == root2) return this val node1 = nodes(root1) val node2 = nodes(root2) if (node1.treeSize < node2.treeSize) { node1.parent = Some(t2) node2.treeSize += node1.treeSize } else { node2.parent = Some(t1) node1.treeSize += node2.treeSize } this } def connected(t1: Int, t2: Int): Boolean = t1 == t2 || root(t1) == root(t2) @tailrec private def root(t: Int): Int = nodes(t).parent match { case None => t case Some(p) => root(p) } } object Main { def solve(sc: => Scanner): Unit = { val S = sc.next println(if (S.toList.groupBy(a => a).toList.map((x) => (x._2.length)).groupBy(a => a).getOrElse(2, List()).length == 6) { S.toList.sorted.fold("")((a, b) => { if (a.toString.length != 0 && a.toString.charAt(a.toString.length - 1) == b) { a.toString.take(a.toString.length - 1) } else (a + b.toString) }).toString } else ("Impossible")) } def gcd(i: Int, j: Int): Int = { if (i < j) (gcd(j, i)) else (if (j == 0) (i) else (gcd(j, i % j))) } def main(args: Array[String]): Unit = { val sc: Scanner = new Scanner(System.in) solve(sc) } }