Unique Sorted by Length

You are given a list of strings. Your task is to remove any duplicate strings and then sort the unique strings according to the following rules:

• First, by their length in ascending order.
• If two strings have the same length, sort them in lexicographical (alphabetical) order.

The input will be provided from stdin and the output should be printed to stdout. The first line of the input contains an integer n representing the number of strings. The next n lines each contain one string. Your program should output the sorted unique strings in a single line, separated by a space. If there are no strings, output an empty line.

Note: If any element is not a valid string, the program should throw an error. However, under normal contest conditions, all inputs will be valid strings.

inputFormat

The first line contains an integer n indicating the number of strings. The following n lines each contain one string.

outputFormat

Print the unique sorted strings on a single line separated by a single space. If there are no strings, output an empty line.

6
pear
apple
orange
pear
banana
grape

pear apple grape banana orange