Correct the chemical formulas

The program is designed to help improve understanding and memorization of chemistry and its formulas.
The user can create formulas by entering them in the appropriate fields, entering their names, choosing their complexity and adding favorites. The user can also redefine the list of all added formulas, the selected formulas will be highlighted.
After creating several formulas, the user can use the test search mode. On this screen, he sees a mixed formula, and he needs to add a formula using mixed characters.