import base64
import datetime

def convert_twitter_image_filename_to_datetime(filename):
    filename_padded = filename + '=' * ((4 - len(filename) % 4) % 4)
    bytes_sequence = base64.urlsafe_b64decode(filename_padded)
    timestamp_bytes = bytes_sequence[:8]
    timestamp_int = int.from_bytes(timestamp_bytes, byteorder='big')
    timestamp_ms = (timestamp_int >> 22) + 1288834974657  # shift 41 bits to 64 bits and add Twitter's epoch time

    # Convert to seconds and then to datetime object
    timestamp_s = timestamp_ms / 1000
    dt = datetime.datetime.fromtimestamp(timestamp_s, tz=datetime.timezone.utc)

    return dt

filename = input("Enter the Twitter image filename: ")
dt = convert_twitter_image_filename_to_datetime(filename)
print("Decoded timestamp:", dt)