A **valid number** can be split up into these components (in order):

- A
**decimal number**or an**integer**. - (Optional) An
`'e'`

or`'E'`

, followed by an**integer**.

A **decimal number** can be split up into these components (in order):

- (Optional) A sign character (either
`'+'`

or`'-'`

). - One of the following formats:
- One or more digits, followed by a dot
`'.'`

. - One or more digits, followed by a dot
`'.'`

, followed by one or more digits. - A dot
`'.'`

, followed by one or more digits.

- One or more digits, followed by a dot

An **integer** can be split up into these components (in order):

- (Optional) A sign character (either
`'+'`

or`'-'`

). - One or more digits.

For example, all the following are valid numbers: `["2", "0089", "-0.1", "+3.14", "4.", "-.9", "2e10", "-90E3", "3e+7", "+6e-1", "53.5e93", "-123.456e789"]`

, while the following are not valid numbers: `["abc", "1a", "1e", "e3", "99e2.5", "--6", "-+3", "95a54e53"]`

.

Given a string `s`

, return `true`

* if *`s`

* is a valid number*.

**Example 1:**

Input:s = "0"Output:true

**Example 2:**

Input:s = "e"Output:false

**Example 3:**

Input:s = "."Output:false

**Example 4:**

Input:s = ".1"Output:true

**Constraints:**

`1 <= s.length <= 20`

`s`

consists of only English letters (both uppercase and lowercase), digits (`0-9`

), plus`'+'`

, minus`'-'`

, or dot`'.'`

.

class Solution {
public boolean isNumber(String s) {
}
}