Input (grade 13): On 18 July 2007 in Johannesburg, South Africa, Nelson Mandela, GraÃ a Machel, and Desmond Tutu convened a group of world leaders to contribute their wisdom, independent leadership and integrity together to the world.
Output (grade 10): On 18 July 2007 in Johannesburg, South Africa, Nelson Mandela, GraÃ a Machel, and Desmond Tutu began a group of world leaders to help the world.