I'm stuck with this assignment where I need to use index-match formula to input values from another sheet.

Google Sheet: <https://docs.google.com/spreadsheets/d/182b4foaNURrAysA9pQ2rtFinU0U1TnwBDNHEkInbjiQ/edit?usp=sharing>

I need to get value from Sheet "Mon-Sun" to show in the sheet "Work hour" using formula. My friend said I should use index-match, but I cannot seem to be able to do it (Only know how to do basic index-match). Been thinking for hours now but cannot find the solution. Please help.