Problem: You are given a string s consisting of |s| small english letters.

In one move you can replace any character of this string to the next character in alphabetical order (a will be replaced with b, s will be replaced with t, etc.). You cannot replace letter z with any other letter.

Your target is to make some number of moves (not necessary minimal) to get string abcdefghijklmnopqrstuvwxyz (english alphabet) as a subsequence. Subsequence of the string is the string that is obtained by deleting characters at some positions. You need to print the string that will be obtained from the given string and will be contain english alphabet as a subsequence or say that it is impossible.

Input

The only one line of the input consisting of the string s consisting of |s| (1 ≤ |s| ≤ 105) small english letters.

Output

If you can get a string that can be obtained from the given string and will contain english alphabet as a subsequence, print it. Otherwise print «-1» (without quotes).

Examples

Input

aacceeggiikkmmooqqssuuwwyy


Output

abcdefghijklmnopqrstuvwxyz


Input

thereisnoanswer


Output

-1

Solution (in JAVA):

Solution:
import java.util.*;
import java.io.*;
public class StringTransformation {
    
    
    
    /************************ SOLUTION STARTS HERE ************************/
    
    
    private static void solve() {
        
        
        char str[] = nextLine().toCharArray();
        TreeSet<Integer> pos[] = new TreeSet[26];
        for(int i = 0; i < 26; i++)
            pos[i] = new TreeSet<>();
        
        for(int i = 0; i < str.length; i++)
            pos[str[i] - 'a'].add(i);
        
        int curr = -1;
        for(int i = 0; i < 26; i++) {
            int min = Integer.MAX_VALUE;
            for(int j = 0; j <= i; j++) {
                Integer ceil = pos[j].higher(curr);
                min = ceil != null ? Math.min(min , ceil) : min;
            }
            
            if(min == Integer.MAX_VALUE) {
                println(-1);
                return;
            }
            
            curr = min;
            str[curr] = (char) ('a' + i);
            
        }
        
        
        println(new String(str));
        
    }
    
    
    
    /************************ SOLUTION ENDS HERE ************************/
    
    
    
    
    
    /************************ TEMPLATE STARTS HERE **********************/
    
    public static void main(String[] args) throws IOException {
        reader = new BufferedReader(new InputStreamReader(System.in));
        writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)), false);
        st     = null;
        solve();
        reader.close();
        writer.close();
    }
    
    static BufferedReader reader;
    static PrintWriter    writer;
    static StringTokenizer st;
    
    static String next()
    {while(st == null || !st.hasMoreTokens()){try{String line = reader.readLine();if(line == null){return null;}            
    st = new StringTokenizer(line);}catch (Exception e){throw new RuntimeException();}}return st.nextToken();}
    static String nextLine()  {String s=null;try{s=reader.readLine();}catch(IOException e){e.printStackTrace();}return s;}             
    static int    nextInt()   {return Integer.parseInt(next());}
    static long   nextLong()  {return Long.parseLong(next());}     
    static double nextDouble(){return Double.parseDouble(next());}
    static char   nextChar()  {return next().charAt(0);}
    static int[]  nextIntArray(int n)         {int[] a= new int[n];   int i=0;while(i<n){a[i++]=nextInt();}  return a;}
    static long[] nextLongArray(int n)        {long[]a= new long[n];  int i=0;while(i<n){a[i++]=nextLong();} return a;}    
    static int[]  nextIntArrayOneBased(int n) {int[] a= new int[n+1]; int i=1;while(i<=n){a[i++]=nextInt();} return a;}            
    static long[] nextLongArrayOneBased(int n){long[]a= new long[n+1];int i=1;while(i<=n){a[i++]=nextLong();}return a;}            
    static void   print(Object o)  { writer.print(o);  }
    static void   println(Object o){ writer.println(o);}
    
    /************************ TEMPLATE ENDS HERE ************************/
    
}