YOu can do it from the Cost / Revenue side.
From the Cost side, you have to split into the main drivers:
- Construction of Olympic stadiums
- Other renovation / construsction
That method will be quite complicated.
Alternatively, you can calculate from the Revenue side:
- Calculate the ticket revenues
- Assume that share of ticket revenues in overall revenues (Rest will be Media Rights, Direct revenues from tourists, etc)
- Assume that Olympics cover only 50% of the total costs and the rest is paid back within the next years with tourists, etc and even generates profits
- Calculate back the total costs