help explain the code

1 = $ = input("enter a list: ") find_word = input("enter the word to find: ") replace = input("enter the word to replace: ") 2 3 4 min 5 n = s.find(find_word) 6 7 8 9 10 if n != -1: while (n != -1): substring = s[0:n] substring = substring + replace substring = substring + s(n + len(find_word): ] 5 = substring n = 5.find(find_word, n + 1, len(s)) 11 12 13 14 15 print(substring) 16