#include <bits/stdc++.h>
using namespace std;
int main(){
  string S;
  cin >> S;
  S += ('a' - 1);
  int N = S.size();
  set<char> st;
  for (int i = 0; i < 26; i++){
    st.insert('a' + i);
  }
  string ans = "zz";
  for (int i = 0; i < N; i++){
    if (st.upper_bound(S[i]) != st.end()){
      string T = S.substr(0, i) + *(st.upper_bound(S[i]));
      ans = min(ans, T);
    }
    if (i < N - 1){
      st.erase(S[i]);
    }
  }
  if (ans == "zz"){
    ans = "-1";
  }
  cout << ans << endl;
}
### 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;
  S += ('a' - 1);
  int N = S.size();
  set<char> st;
  for (int i = 0; i < 26; i++){
    st.insert('a' + i);
  }
  string ans = "zz";
  for (int i = 0; i < N; i++){
    if (st.upper_bound(S[i]) != st.end()){
      string T = S.substr(0, i) + *(st.upper_bound(S[i]));
      ans = min(ans, T);
    }
    if (i < N - 1){
      st.erase(S[i]);
    }
  }
  if (ans == "zz"){
    ans = "-1";
  }
  cout << ans << endl;
}
```