Task: Question Answering
Input (English): Passage: On 10 March 1914, the suffragette Mary Richardson walked into the National Gallery and attacked Velázquez's canvas with a meat cleaver. Her action was ostensibly provoked by the arrest of fellow suffragette Emmeline Pankhurst the previous day, although there had been earlier warnings of a planned suffragette attack on the collection. Richardson left seven slashes on the painting, particularly causing damage to the area between the figure's shoulders. However, all were successfully repaired by the National Gallery's chief restorer Helmut Ruhemann.Richardson was sentenced to six months' imprisonment, the maximum allowed for destruction of an artwork. In a statement to the Women's Social and Political Union shortly afterwards, Richardson explained, "I have tried to destroy the picture of the most beautiful woman in mythological history as a protest against the Government for destroying Mrs. Pankhurst, who is the most beautiful character in modern history." She added in a 1952 interview that she didn't like "the way men visitors gaped at it all day long".The feminist writer Lynda Nead observed, "The incident has come to symbolize a particular perception of feminist attitudes towards the female nude; in a sense, it has come to represent a specific stereotypical image of feminism more generally." Contemporary reports of the incident reveal that the picture was not widely seen as mere artwork. Journalists tended to assess the attack in terms of a murder (Richardson was nicknamed "Slasher Mary"), and used words that conjured wounds inflicted on an actual female body, rather than on a pictorial representation of a female body. The Times described a "cruel wound in the neck", as well as incisions to the shoulders and back. 
Question: What is the last name of the person whose painting was successfully repaired by the National Gallery?
Output (English): Velázquez.