给出12小时AM / PM格式的时间，将其转换为军事（24小时）时间。

注意：午夜是12小时制的凌晨12:00:00和24小时制的00:00:00。中午是12小时制的12:00:00 PM和24小时制的12:00:00。

例子 ：

输入：晚上11:21:30
输出：23：21：30

输入：上午12:12:20
输出：00：12：20

# Python program to convert time

# from 12 hour to 24 hour format

# Function to convert the date format

def convert24(str1):

# Checking if last two elements of time

# is AM and first two elements are 12

if str1[-2:] == "AM" and str1[:2] == "12":

return "00" + str1[2:-2]

# remove the AM

elif str1[-2:] == "AM":

return str1[:-2]

# Checking if last two elements of time

# is PM and first two elements are 12

elif str1[-2:] == "PM" and str1[:2] == "12":

return str1[:-2]

else:

# add 12 to hours and remove PM

return str(int(str1[:2]) + 12) + str1[2:8]

# Driver Code

print(convert24("08:05:45 PM"))