Please help it has to be simple for someone

Hello,
I need a Excel Formula
What i need it to do is take information from the A cells and from the B cells and put it into C cells.
Now here is the but for this question. I need it to display text or numbers.
Example
If i have 545 in sell A1 and i have nothing in cell b1 i want it to show 545 in cell C1
If i have the part name in A1 and nothing in cell b1 i want it to display the part name in C1

Now if i have nothing in A1 but the name of the part or a number in B1 i would like it to display in C1

and the last part is if i have information in both A1 and B1 i would like to show the information (text or number) from A1 in C1 ignoring the value in B1.