Compare two rows in first column, having text value in same integer, add values of all row

Hi,
I am facing a issue, My worksheet having too many rows, some of the row serial no marked as 1, 1(A), 2, 2(A), 3, 4, 5, 5(A).... and remaining columns having some values. My needs is if having serial no. 1 & 1 (A) combined and add values in both rows placed in 1's row.
Any one please help making a formula for the same