How to sum INT-INT ranges in Google Sheets?

Question

Google Sheets

Suppose there is a column in which the data can be ordinary numbers or ranges:
100
2000
300-500
850
500-1500
at the output I want to get the result of INT-INT
in this case 3750-4950
and if they are equal, then just a number.
Help with the formula. The variant with splitting the data into 2 columns does not suit me.

Answer 1

1. Write a macro, for example, in Google Drive it is written in JS (if you really want to completely without extra columns).
   For example, using the following formulas (in LO):
   Left part =IFERROR(MID(A2,1,FIND("-",A2)-1),A2)+0
   Right part =IFERROR(MID(A2,FIND("-",A2)+1,LEN(A2)-1),A2)+0
   "+0" serve to turn the text into a number.
   Sum --=IF(B7=C7,B7,CONCATENATE(B7,"-",C7))