A palindrome is a word that reads the same way both from left to right and from right to left, for example, in English such words are “radar”; and «racecar».
Sveta is studying English and decided to take part in a distance competition for English speakers. But, when she wrote the answer to the task “find the longest word that is a palindrome”, she made a mistake and pressed one extra key on the keyboard.
Determine which letter needs to be removed in the word Sveta has typed so that this word becomes a palindrome.
Input
The program receives as input a string of lowercase English letters containing at least 2 and no more than 100,000 characters.
Imprint
The program should output a single number – the number of the letter in the string that when removed becomes a palindrome. If removing any letter does not make the word a palindrome, the program should print the number 0.
Examples
| # |
Input |
Output |
| 1 |
raceczar |
6 |
| 2 |
car |
0 |