Exercises G25

A mobile simulator game for completing challenges and collecting diamonds does not allow choosing second challenge after level 17 and when level 15 is reached, the diamonds from completed challenges are not calculated.

Steps to reproduce
1. Open game app
2. Play and pass level 15
3. Check total diamond number
4. Choose second challenge after reaching level 17

Expected result
The game app should calculate total diamond number and the user can work on two challenges at the same time.

Actual Results
The game app does not calculate total diamond number and the user cannot work on two challenges at the same time.