# Fill in the next numbers [tag:code-golf] [tag:array] [tag:number]

Given a list of integers, output a list where the \$ i \$th element of the list equals the first number in the input list which is \$ \ge i \$, until there are no such numbers.

For example, if the input is the first 5 prime numbers:

```
2 3 5 7 11
```

then we "expand" the sequence out to show where the gaps are:

```
  2 3   5   7        11     # primes
1     4   6   8 9 10        # gaps
```

Now we fill in the blanks with the next number that is in the sequence in each case:

```
2 2 3 5 5 7 7 11 11 11 11
1     4   6    8  9 10
```

This is our output.

## Test cases
```
[1]               -> [1]
[3]               -> [1, 2, 3]
[1, 2, 3]         -> [1, 2, 3]
[2, 3, 5, 7, 11]  -> [2, 2, 3, 5, 5, 7, 7, 11, 11, 11, 11]
```

## Rules
- You may assume the input list is non-empty, strictly increasing, and only contains positive integers
- You may use any [standard I/O method](https://codegolf.meta.stackexchange.com/q/2447)
- [Standard loopholes](https://codegolf.meta.stackexchange.com/q/1061) are forbidden
- This is [tag:code-golf], so the shortest code in bytes wins

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