```
consonant_letters = ['B', 'C', 'D', 'F', 'G', 'H', 'J', 'K', 'L', 'M', 'N', 'P', 'Q', 'R', 'S', 'T', 'V', 'X', 'Z']
for x in range(9999):
    for y in range(consonant_letters):
        for z in range(consonant_letters):
            for a in range(consonant_letters):
                print(f'{x} {y} {z} {a}')

```

\*And what I get is this 

> 
> TypeError: 'list' object cannot be interpreted as an integer
> 
> 
> 

\*I'm trying to print all the numbers in the Spanish License Plate system, transform it into a list and lastly, do an input function where the user enters a certain license plate, and the program tells him how many license plates there are until this license plate system ends. 

\*Edit: I found out now the only thing I have left and can't figure out is how to formulate the input function. Here's the solution:

```
consonant_letters = ['B', 'C', 'D', 'F', 'G', 'H', 'J', 'K', 'L', 'M',    
'N', 'P', 'Q', 'R', 'S', 'T', 'V', 'X', 'Z']

for x in range(10000):
    break
    if x < 1000 and x > 99:
        x = f"0{x}"
    elif x < 100 and x > 9:
        x = f"00{x}"
    elif x < 10:
        x = f"000{x}"
    for y in consonant_letters:
        for z in consonant_letters:
            for a in consonant_letters:
                print(f'{x} {y} {z} {a}')

```

\*I tried introducing the input function so the user can introduce a certain license plate number and I will detect if it exists but there's a problem. 
Here's what I tried:

```
`consonant_letters = ['B', 'C', 'D', 'F', 'G', 'H', 'J', 'K', 'L',      
'M', 'N', 'P', 'Q', 'R', 'S', 'T', 'V', 'X', 'Z']
for x in range(10000):
if x < 1000 and x > 99:
    x = f"0{x}"
elif x < 100 and x > 9:
    x = f"00{x}"
elif x < 10:
    x = f"000{x}"
for y in consonant_letters:
    for z in consonant_letters:
        for a in consonant_letters:
            list_1 = f'{x} {y}{z}{a}'
            license_plate_user = input("Write the license plate: ")
            print(license_plate_user in list_1)`

```

\*When I introduce any other license plate that's not 0000 BBB (the first one) it says False. I know this means that the loop gets executed only one time, but I don't know how to fix it.

\*Edit; I figured out how to get the loop executed and then formulate the input but I have one more question left. Is there an operation I can write knowing a specific license plate to know how many there are left?

```
consonant_letters = ['B', 'C', 'D', 'F', 'G', 'H', 'J', 'K', 'L', 'M',   
'N', 'P', 'Q', 'R', 'S', 'T', 'V', 'X', 'Z']
for x in range(10000):
if x < 1000 and x > 99:
    x = f"0{x}"
elif x < 100 and x > 9:
    x = f"00{x}"
elif x < 10:
    x = f"000{x}"
for y in consonant_letters:
    for z in consonant_letters:
        for a in consonant_letters:
            list1 = f'{x} {y}{z}{a}'
            if "9999 ZZZ" in list1:
                license_plate_user = input("Write the license plate: ")
                license_plate_user in list1
                if license_plate_user:
                    print("Operation I do not know yet")
                else:
                    print("Wrong values")

```

\*Edit: I found a way but it's not working and I don't know why:

```
consonant_letters = ['B', 'C', 'D', 'F', 'G', 'H', 'J', 'K', 'L', 'M', 
'N', 'P', 'R', 'S', 'T', 'V', 'X', 'Z']
total_number_of_license_plates = 80000000
for x in range(10000):
    if x < 1000 and x > 99:
        x = f"0{x}"
    elif x < 100 and x > 9:
        x = f"00{x}"
    elif x < 10:
        x = f"000{x}"
    for y in consonant_letters:
        for z in consonant_letters:
            for a in consonant_letters:
                list1 = f'{x} {y}{z}{a}'
                if "9999 ZZZ" in list1:
                    license_plate_user = input("Write the license   
plate: ")
                    license_plate_user in list1
                    if license_plate_user:
                        print(list1.index(license_plate_user))
                        license_plates_left = 
total_number_of_license_plates - list1.index(license_plate_user)
                        print(f'There are {license_plates_left} license 
plates left')
                    else:
                        print("Wrong values")

```

And what I get is:

> 
> ValueError: substring not found
> 
> 
>