Please, check if you need a Visa to visit Brazil. Your may use this official Country List for information or obtain further information in http://www.braziltour.com/site/en/dicas_turista_passaporte/materia.php
You find a list of Brazilian Missions Abroad (Embassies, Consulates and Vice-Consulates, Delegartions, Missions and Offices) at the site of the Brazilian Ministry of External Relations.
Messagem from the ACM Headquartes:The Association for Computing Machinery does not issue formal invitation letters for visas to attend ACM sponsored conferences. We can however issue a Visa support letter. For Visa support letters, please send all requests to the NEW person in charge for this at ACM, Laura Bucci (Bucci@hq.acm.org), with the following information.
- Name and mailing address as it appears on your passport
- The name of the conference you wish to attend
- Your Registration Confirmation Number
- If you are the author of any papers accepted for the conference, please provide the title
- A valid fax number and current mailing address
*Visa support letters are NOT issued via email