# Consecutive Ones

You are given a list of integers `nums`

which contains at least one `1`

. Return whether all the `1`

s appear consecutively.

**Constraints**

`1 ≤ n ≤ 100,000`

where`n`

is the length of`nums`

https://binarysearch.com/problems/Consecutive-Ones

## Examples

### Example 1

**Input**

- nums =
`[0, 1, 1, 1, 2, 3]`

**Output**

- answer =
`True`

**Explanation**

All the `1`

s appear consecutively here in the middle.

### Example 2

**Input**

- nums =
`[1, 1, 0, 1, 1]`

**Output**

- answer =
`False`

**Explanation**

There’s two groups of consecutive `1`

s.

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