10076: ABC345 —— A - Leftrightarrow
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Description
You are given a string $S$ consisting of `<`, `=`, and `>`.
Determine whether $S$ is a bidirectional arrow string.
A string $S$ is a bidirectional arrow string if and only if there is a positive integer $k$ such that $S$ is a concatenation of one `<`, $k$ `=`s, and one `>`, in this order, with a length of $(k+2)$.
Determine whether $S$ is a bidirectional arrow string.
A string $S$ is a bidirectional arrow string if and only if there is a positive integer $k$ such that $S$ is a concatenation of one `<`, $k$ `=`s, and one `>`, in this order, with a length of $(k+2)$.
Input
The input is given from Standard Input in the following format:
```
$S$
```
```
$S$
```
Output
If $S$ is a bidirectional arrow string, print `Yes`; otherwise, print `No`.
Constraints
- $S$ is a string of length between $3$ and $100$, inclusive, consisting of `<`, `=`, and `>`.
Sample 1 Input
<====>
Sample 1 Output
Yes
<====> is a concatenation of one <, four =s, and one >, in this order, so it is a bidirectional arrow string.
Hence, print Yes.
Hence, print Yes.
Sample 2 Input
==>
Sample 2 Output
No
==> does not meet the condition for a bidirectional arrow string.
Hence, print No.
Hence, print No.
Sample 3 Input
<>>
Sample 3 Output
No