#include<iostream>
#include<string>
#include<set>
#include<algorithm>
using namespace std;

int main() {
	string s; cin >> s;

	if (s.size() < 26) {
		for (char c = 'a'; c <= 'z'; c++) {
			if (s.find(c) == -1) {
				cout << s << c << endl;
				return 0;
			}
		}
	}
	else {
		set<char>x;
		while (!s.empty()) {
			char c = s.back(); s.pop_back();
			x.insert(c);
			if (c != *x.rbegin()) {
				cout << s << *x.upper_bound(c) << endl;
				return 0;
			}
		}
		cout << -1 << endl;
	}

	return 0;
}
### 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<iostream>
#include<string>
#include<set>
#include<algorithm>
using namespace std;

int main() {
	string s; cin >> s;

	if (s.size() < 26) {
		for (char c = 'a'; c <= 'z'; c++) {
			if (s.find(c) == -1) {
				cout << s << c << endl;
				return 0;
			}
		}
	}
	else {
		set<char>x;
		while (!s.empty()) {
			char c = s.back(); s.pop_back();
			x.insert(c);
			if (c != *x.rbegin()) {
				cout << s << *x.upper_bound(c) << endl;
				return 0;
			}
		}
		cout << -1 << endl;
	}

	return 0;
}
```