package main

import (
	"fmt"
	"sort"
	"strings"
)

func main() {
	var S string
	fmt.Scan(&S)
	A := "abcdefghijklm"
	s := strings.Split(S, "")
	a := strings.Split(A, "")
	sort.Strings(s)
	sort.Strings(a)
	var e bool
	for i := 0; i < len(a); i++ {
		if s[i] != a[i] {
			e = true
		}
	}
	// if len(a) != len(s) {
	// e = true
	// }
	// log.Println(s)
	// log.Println(a)
	if e {
		fmt.Println("Impossible")
	} else {
		for _, m := range a {
			fmt.Println(m)
		}
	}
}