Sum column

My formula is not working out, so I'm trying to SUM up a column E which has 50 rows, from row 2 to row 50, so E2:E50, BUT also subtracting the value of each E cell by 1 before adding them all together in the column. The last step is adding the condition that D="Y".

I'm not sure if I should use a SUM condition or a COUNTIF condition...

Could you show me the final output look you want, because i dont understand that what is D="Y"