How to write a formula with a YES/NO function?

Question

excel

All the best, dear experts!
Please advise how I can implement this idea in Google Sheets:
Columns ABCD
Row 1
Cell A1 is equal to value 15
Cell B1 is equal to value "Yes" or "No"
Cell C1 is equal to value 5
Cell D1 is equal to the sum of A1+C1
The main condition is:
If B1 equals "Yes", then A1 is added to C1.
But if B1 is "NO", then nothing is added to A1.

Thank you.

Answer 1

=IF(B1="ДА";A1+C1;A1)