# creating a matrix from blocks

I am new to SAGE. I need to create a matrix by using matrices of different sizes. For example:

```
Abar= [(A + B), C]
[ D , E]
```

where A and B are 2x2's, C is a 2x1, D is a 1x2, and E is a 1x1. I do not need Abar to be a partitioned matrix. Thanks much.