PLEASE write a code in PYTHON : A string of words will be called a "chain" if each word in the string begins with a letter ending in the previous word. The first word begins with a letter where the last word ends. For example, the following string is a necklace: The even numbers saved date Write a function whose signature - isChain (str) The function will get a string of words and return True if the string is a string and False if not. It can be assumed that the string consists of only small English letters and spaces, where between every two words there is exactly one space