Sum values only one time

Hello everyone,

I have a table with 2 columns: 'Code' and 'Values'. The Code can be repeated.

The Values column is the same for each code, so 2 Values for 'CodeA' are equal to each other, and 2 values for 'CodeB' are also the same.

What I need is a measure to sum ONE TIME each value for each code, so in the example of the table below I would only need to sum 1 value for CodeA and 1 value for CodeB and the value for CodeC (3+5+7)

I thought a way that is using an auxiliar column named 'Unique' which is '1' if it is the first time the Code appears, and '0' if not, and use a CALCULATE function later. But I couldn't find a way to make this 'Unique' columns.

The Unique column would be:

Code     Value   Unique

CodeA   3         1

CodeA   3         0

CodeB   5         1

CodeB   5         0

CodeC   7         1

Thanks in advance!