SSRS 2012: Subtract multiple column values from one

Hi All, 

Scenario:

Col1Col2 Col3 Col4 Col5

5020 2010(To calculate)

In my report, I have 5 columns, first 4 have numeric values (BIGINT to be precise).

What I need:
Col5=Col1-Col2-Col3-Col4 (Ideally Col5 will be 0 always but I just need find the difference)

How do I subtract multiple columns from Col1?? 

Any help is highly appreciated!!

Thanks in advance,
Regards,
Mandar