I've several matrices, each one stored in a NumPy array and I would like to add them all.

```
a1=np.load("20130101T054446")
a2=np.load("20130102T205729")
a3=np.load("20130104T153006")
a4=np.load("20130113T130758")
a5=np.load("20130113T212154")

```

I know its possible to add them in this away:

```
z=a1+a2+a3+a4+a5

```

But, since I have hundreds of matrices I would like to do it in a easy away. 

Is there any way to import all at the same time and ascribe it to different variables?