How I can get column name of last non zero value in row, using Excel functions.

Example:

A:E - columns with values
x - function result

```
A B C D E x

0 0 1 0 0 C
1 0 2 1 2 E
0 1 1 0 1 E
1 1 1 1 1 E
0 0 0 0 0 

```