I need to write a simple Python program to solve this issue. I have most of the program written, but when I run the second example, the result is incorrect. Examples 1 and 3 work just fine.

Write a program to calculate the number of seconds since midnight. For example, suppose the time is 1:02:05 AM. Since there are 3600 seconds per hour and 60 seconds per minute, it has been 3725 seconds since midnight (3600 * 1 + 2 * 60 + 5 = 3725). The program asks the user to enter four pieces of information: hour, minute, second, and AM/PM. The program will calculate and display the number of seconds since midnight. [Hint: be very careful when the hour is 12].

Examples for testing code:

1. Enter hour: 1
Enter minute: 2
Enter second: 5
Enter AM or PM: AM
Seconds since midnight: 3725

2. Enter hour: 11
Enter minute: 58
Enter second: 59
Enter AM or PM: PM
Seconds since midnight: 86339

3. Enter hour: 12
Enter minute: 7
Enter second: 20
Enter AM or PM: AM
Seconds since midnight: 440

Here is the code that I have written:

```python
hour = float(input("Enter hour: "))
minute = float(input("Enter minute: "))
second = float(input("Enter second: "))
am_pm = input("Enter AM or PM: ")

if am_pm.lower() == "am" and hour == 12:
hour = 0

seconds_since_midnight = (3600 * hour) + (minute * 60) + second
print("Seconds since midnight:", seconds_since_midnight)
```

Thank you in advance for your help!