Simplify the following text for a Grade 11 native English-speaking person.
Original: In 1978 , Gerry Adams became joint vice-president of Sinn FÃ in and a key figure in directing a challenge to the Sinn FÃ in leadership of President RuairÃ Ã `` BrÃ daigh and joint vice - president DÃ ithÃ Ã `` Conaill .
Simplified: In 1978 , Gerry Adams became joint-vice-president of Sinn FÃ in and he led a challenge to the Sinn FÃ in leadership of President RuairÃ Ã `` BrÃ daigh and joint-Vice President DÃ ithÃ Ã `` Conaill .