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Find the garden of Eden

The Fibonacci sequence starts with `[1,1]` and then continues to the right  with each number being the sum of the previous number. For example the first 10 terms are `[1,1,2,3,5,8,13,21,34,55]`.

We can also extend the sequence to the left, trying to keep the rules consistent. In order for `1` to follow `1`, there must have been a proceeding `0`. In order to extend to the left we add the difference of the first two numbers (second number minus first). This gets us everything to the left of the start too

```
...,13,-8,5,-3,2,-1,1,0,1,1,2,3,5,8,13,21,34,55,...
```

A common idea is to take the rules of the Fibonacci sequence but start with a different seed. For example,

* if we start with `[45,83]`:
  ```
  ...,55,-24,31,7,38,45,83,128,211,339,550,889,...
  ```
* if we start with `[1,2,1]`
  ```
  ...,5,-3,2,-1,1,0,1,1,2,1,3,4,7,11,18,29,47,...
  ```

We will call a seed list like this the "Garden of Eden" for the particular sequence.

Our task today will be to take a portion of a sequence and work out where the Garden of Eden is. That is we will find the *smallest* list that could seed the larger sequence.

This can be done by taking the input following the following algorithm:
* If the last entry is the sum of the two entries before it, remove it and recurse.
* If the third entry is the sum of the two entries before it, remove the first entry and recurse.
* If neither of these holds return the input list.

Sometimes the answer is ambiguous. This happens exactly when there is a Garden of Eden of size 2. For example if the input is `[1,1,2]` then both `[1,1]` and `[1,2]` generate the larger sequence. In this case both are acceptable outputs.

* **Input** A sequence of integers of length at least 2.
* **Output** A minimal Garden of Eden for the sequence generated by the input sequence.

This is code-golf. The goal is to minimize the size of your source code as measured in bytes.


## Test cases

```
[2,1,3,1,4,5,9,14] -> [1,3,1]
[17,-13,4,-9,6,-3,3,0,3,3,6,9] -> [4,-9,6]
[1,1,3,4,7,11,18,29,47,75] -> [1,1,3,4,7,11,18,29,47,75]
[-1,1,0,1,1,-1,1,0,1,1] -> [1,1,-1,1]
```

Ambiguous cases:
```
[1,1,2,3,5,8,13,21,34,55] -> [5,8]
[-1,3,2,5,7,12,19,31,50,81] -> [3,2]
[34,55] -> [0,1]
```