The Unique Numerical Association of Language (UNAL) is an association created to conserve only numbers in different texts. In fact, numbers are so important for UNAL, that its lemma is: 'people can communicate only using digits'.

Mr. Potato Head, the head of the UNAL has assigned you a task to help them to achieve the goal of the association.

Given a text $$$T$$$ you have to find the longest non-empty prefix of $$$T$$$ consisting only of digits, for the UNAL this is enough to understand the whole text.

Input consists of a single line with a text $$$T$$$ without spaces.

The length of the text is between $$$1$$$ and $$$2 * 10^5$$$

Print one line with the longest non-empty numeric prefix of $$$T$$$, if there is no such prefix print $$$-1$$$ instead.