Figure 5 shows an algorithm for a simple authentication routine. Parts of the algorithm are missing and have been replaced with the labels L1 to L4.

Figure 5
login ← False
REPEAT
username ← ""
WHILE username = ""
OUTPUT 'Enter username: '
username ← L1
ENDWHILE
password ← ""
WHILE password = ""
OUTPUT 'Enter password: '
password ← USERINPUT
ENDWHILE
storedPassword ← getPassword(L2)
IF storedPassword = L3 THEN
OUTPUT L4
ELSE
IF password = storedPassword THEN
login ← True
ELSE
OUTPUT 'Try again.'
ENDIF
ENDIF
UNTIL login = True
OUTPUT 'You are now logged in.'
State the items from Figure 6 that should be written in place of the labels in the algorithm in Figure 5. You will not need to use all the items.

Figure 6

-1	OUTPUT	0
username	True	SUBROUTINE
1	User not found	""
USERINPUT	password	Wrong password

Analyse each label in the context of the pseudo-code. 1. **L1:** `username ← L1`. This line is inside a loop that prompts the user to "Enter username:". The purpose is to get input from the user and store it in the `username` variable. The correct item from Figure 6 is `USERINPUT`. 2. **L2:** `storedPassword ← getPassword(L2)`. The `getPassword` subroutine needs to know which user's password to look up. The username has just been entered by the user and is stored in the `username` variable. Therefore, L2 should be `username`. 3. **L3:** `IF storedPassword = L3 THEN`. This `IF` statement handles the case where the user does not exist. The problem description states that `getPassword` returns an empty string if the username does not exist. Therefore, the code needs to check if `storedPassword` is an empty string. The correct item is `""`. 4. **L4:** `OUTPUT L4`. This is the output shown when the username was not found (as determined by the `IF` statement for L3). The appropriate message is `User not found`.