Sum automatically every cell in multiple rows

[Luchian]

Hello,

I want a formula who generate automatically all posibility to sum, one by
one, every cell in row1 whit every cell in row 2 etc...

A B C
1 3 3(A1+A2)
2 4 5(A1+B2)
5(B1+A2)
7(B1+B2)

So... i want the formula who generate in column C automatically all 4
results if row1 and row 2 have 2 elements, all 9 results if row1 and row2
have 3 elements...

TNX

 

[Luchian]

Please help me with this formula...if i was not explicite, tell me. Thank you
(I'm desperate, i don't have time to make manual all the formula to add every
cell in row1 to every cell in row 2, 3....).