Practice Parsing and Parenthesis with the exercise "Ted's compiler"

Learning Opportunities

This puzzle can be solved using the following concepts. Practice using these concepts and improve your skills.

Parsing

Statement

Goal

Ted wants to develop a compiler and knows that one of the most important elements in a compiler is its parser

Parsing, syntax analysis, or syntactic analysis is the process of analyzing a string of symbols, either in natural language, computer languages or data structures, conforming to the rules of a formal grammar.

https://en.wikipedia.org/wiki/Parsing

Today, Ted is concerned with an abstract instruction which is composed of the characters < and > , which he will use on the design of his language, T++ :D.

He understand that, for an expression to be valid, a < symbol must always have a matching > character somewhere (nested expression are valid) after it. In addition, each > symbol must exactly match a < symbol.

So, for instance, the instructions:

<<>>

<>

<><>

are all valid. While:

>>

><><

are not.

Given expression which represent some instructions to be analyzed by Ted's compiler, you should tell the length of the longest prefix of this expression that is valid, or 0 if there is not such a prefix.

Input

Input will consist of a single line, representing a possible expression in T++.

Output

You should output the length of the longest prefix that is valid or 0 if there is not such a prefix

Constraints

1 ≤ The length of line ≤ 100

Example

Input

<<>>>

Output

Solve it

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