def PythagTripCheck():
    sidesCount=0
    smallSideDone=False
    mediumSideDone=False
    largeSideDone=False
    while sidesCount<3:
        whatSide=input("What side would you like to enter first? 'Small', 'Medium' or 'Large'?")
        if whatSide=="Small" or "small" or "S" or "s":
            if smallSideDone=True:
                print("Hey! You've already inputted a small side!")
            else:
                smallSide=input("Enter the length of the small side:")
                if smallSide.isdigit() == False:
                    print("The small side contains a character which is not a number, your numbers have been reset, try again")
                    PythagTripCheck()
                else:
                    sidesCount=sidesCount+1
                    smallSideDone=True
        elif whatSide=="Medium" or "medium" or "M" or "m":
            if mediumSideDone=True:
                print("Hey! You've already inputted a medium side!")
            else:
                mediumSide=input("Enter the length of the medium side:")
                if mediumSide.isdigit() == False:
                    print("The medium side contains a character which is not a number, your numbers have been reset, try again")
                    PythagTripCheck()
                else:
                    sidesCount=sidesCount+1
                    mediumSideDone=True
        elif whatSide=="Large" or "large" or "L" or "L":
            if largeSideDone=True:
                print("Hey! You've already done a large side!")
            else:
                largeSide=input("Enter the length of the large side")
                if largeSide.isdigit() == False:
                    print("The large side contains a character which is not a number, your numbers have been reset, try again")
                    PythagTripCheck()
                else:
                    sidesCount=sidesCount+1
                    largeSideDone=True
        else:
            print("Please try again")