Write a {Java} program which reads in a {paragraph}
in which words to be indexed have been marked and prints out {the}
{paragraph} with {the} indexing marks removed and {the} lines numbered
followed by an {index} in alphabetical order listing {the} {line} numbers
for each {word}  Words to be indexed are marked by placing curly
braces around them.  Note in {the} following example that it is OK to
list a repeated {line} number if the {word} is marked more than once in
that {line} (e.g. `key').  Also, only list marked occurrences of a {word}
For instance, `computer' occurs on {line} 5, but it is not enclosed in
braces and so {line} 5 is not listed in the {index} entry for `computer'.