#include <bits/stdc++.h>
using namespace std;
int main(){
	string s;
	cin>>s;
	int a[33]={0};
	for(int i=0;i<s.length();i++){
		a[s[i]-'a']=1;
	}
	if(s=="zyxwvutsrqponmlkjihgfedcba"){
		puts("-1");
		return 0;
	}
	for(int i=0;i<26;i++){
		if(!a[i]){
			cout<<s<<char('a'+i)<<endl;
			return 0;
		}
	}
	int i=0,t=0;
	for(i=s.length()-1;i>=0;i--){
		a[s[i]-'a']=0;
		if(s[i]>s[i-1]){
			t=s[i-1]-'a';
			break;
		}
	}
	for(int j=0;j<i-1;j++){
		cout<<s[j];
	}
	for(int i=t;i<26;i++){
		if(!a[i]){
			cout<<char('a'+i)<<endl;
			break;
		}
	}
}
/*
abcdefghijklmnopqrstuvwxyz
yzxwvutsrqponmlkjihgfedcba
*/
### Prompt

In cpp, your task is to solve the following problem:

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

### Response

```cpp
#include <bits/stdc++.h>
using namespace std;
int main(){
	string s;
	cin>>s;
	int a[33]={0};
	for(int i=0;i<s.length();i++){
		a[s[i]-'a']=1;
	}
	if(s=="zyxwvutsrqponmlkjihgfedcba"){
		puts("-1");
		return 0;
	}
	for(int i=0;i<26;i++){
		if(!a[i]){
			cout<<s<<char('a'+i)<<endl;
			return 0;
		}
	}
	int i=0,t=0;
	for(i=s.length()-1;i>=0;i--){
		a[s[i]-'a']=0;
		if(s[i]>s[i-1]){
			t=s[i-1]-'a';
			break;
		}
	}
	for(int j=0;j<i-1;j++){
		cout<<s[j];
	}
	for(int i=t;i<26;i++){
		if(!a[i]){
			cout<<char('a'+i)<<endl;
			break;
		}
	}
}
/*
abcdefghijklmnopqrstuvwxyz
yzxwvutsrqponmlkjihgfedcba
*/
```