Question : SQL sum

I have a stored procedure that does the following

take in parameter

@Par1 int
@Par2 int
@Par3 int

'does some stuff to give both @par1 and @par2 numeric value


How would i add the @par1 + @par2 to give @par3 a value

@par3 = @par1 + @par2

Answer : SQL sum

set @par3 = @par1 + @par2