Secret Santa

Secret Santa is a Christmas tradition in which members of a group are randomly assigned a person to whom they give a gift.

You are given a list of names. Write a script that teams persons from different families, if possible.

Example 1

The givers are randomly chosen but don't share family names with the receivers.

Input

@names = (
    'Mr. Wall',
    'Mrs. Wall',
    'Mr. Anwar',
    'Mrs. Anwar',
    'Mr. Conway',
    'Mr. Cross',
);

Output

Mr. Conway -> Mr. Wall
Mr. Anwar -> Mrs. Wall
Mrs. Wall -> Mr. Anwar
Mr. Cross -> Mrs. Anwar
Mr. Wall -> Mr. Conway
Mrs. Anwar -> Mr. Cross

Example 2

One gift is given to a family member.

Input

@names = (
    'Mr. Wall',
    'Mrs. Wall',
    'Mr. Anwar',
);

Output

Mr. Anwar -> Mr. Wall
Mr. Wall -> Mrs. Wall
Mrs. Wall -> Mr. Anwar