1. Write a Python program to find the second smallest number in a list.
# input
# second_smallest([1, 2, -8, -2, 0])
# output
# -2

2. Write a Python program to change a given string to a new string where the first and last chars have been exchanged 

3. Write a Python function that takes a list of words and returns the length of the longest one 

4. Write a Python program to remove the nth index character from a nonempty string 

5. Check if a given key already exists in a dictionary
# input
# d = {1: 10, 2: 20, 3: 30, 4: 40, 5: 50, 6: 60}
# is_key_present(5)
# is_key_present(9)
# output
# Key is present in the dictionary                                                                              
# Key is not present in the dictionary