Gotou just received a dictionary. However, he doesn't recognize the language used in the dictionary. He did some analysis on the dictionary and realizes that the dictionary contains all possible diverse words in lexicographical order.

A word is called diverse if and only if it is a nonempty string of English lowercase letters and all letters in the word are distinct. For example, `atcoder`, `zscoder` and `agc` are diverse words while `gotou` and `connect` aren't diverse words.

Given a diverse word S, determine the next word that appears after S in the dictionary, i.e. the lexicographically smallest diverse word that is lexicographically larger than S, or determine that it doesn't exist.

Let X = x_{1}x_{2}...x_{n} and Y = y_{1}y_{2}...y_{m} be two distinct strings. X is lexicographically larger than Y if and only if Y is a prefix of X or x_{j} > y_{j} where j is the smallest integer such that x_{j} \neq y_{j}.

Constraints

* 1 \leq |S| \leq 26
* S is a diverse word.

Input

Input is given from Standard Input in the following format:


S


Output

Print the next word that appears after S in the dictionary, or `-1` if it doesn't exist.

Examples

Input

atcoder


Output

atcoderb


Input

abc


Output

abcd


Input

zyxwvutsrqponmlkjihgfedcba


Output

-1


Input

abcdefghijklmnopqrstuvwzyx


Output

abcdefghijklmnopqrstuvx
import java.util.*;

// ARC 93-D
// https://beta.atcoder.jp/contests/arc093/tasks/arc093_b

public class Main {
	
	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);

		String s = in.next();
		
		if (s.equals("zyxwvutsrqponmlkjihgfedcba")) {
			System.out.println(-1);
		} else {
			int[] count = new int[26];
			for (int i = 0; i < s.length(); i++) {
				count[s.charAt(i) - 'a'] += 1;
			}
			
			int index = -1;
			for (int i = 0; i < count.length; i++) {
				if (count[i] == 0) {
					index = i;
					break;
				}
			}
			
			if (index >= 0) {
				System.out.printf("%s%c\n", s, index + 'a');
			} else {
				count = new int[26];
				int stringTill = 0;
				char tailingCharacter = ' ';
				boolean answerFound = false;

				for (int i = s.length() - 1; i >= 0 && !answerFound; i--) {
					int cindex = s.charAt(i) - 'a';
					for (int j = cindex + 1; j < 26; j++) {
						if (count[j] > 0) {
							tailingCharacter = (char) (j + 'a');
							stringTill = i;
							answerFound = true;
							break;
						}
					}
					count[cindex] += 1;
				}
				
				for (int i = 0; i < stringTill; i++) {
					System.out.printf("%c", s.charAt(i));
				}
				System.out.printf("%c\n", tailingCharacter);
				
//				char lastHeadChar = s.charAt(s.length() - 1);
//				boolean answerFound = false;
//				for (int i = s.length() - 2; i >= 0 && !answerFound; i--) {
//					if (s.charAt(i) < lastHeadChar) {
//						answerFound = true;
//						index = i;
//					}
//				}
//				
//				if (answerFound) {
//					for (int i = 0; i < index; i++) {
//						System.out.printf("%c", s.charAt(i));
//					}
//					System.out.printf("%c\n", lastHeadChar);
//				} else {
//					System.out.printf("%c\n", 1 + s.charAt(0));
//				}
			}
		}
	}
}