Task: Question Answering
Input (English): Passage: One British soldier, Bradley Tinnion, was killed in the operation. Another twelve soldiers were injured, one seriously. The British Ministry of Defence (MoD) did not officially acknowledge the involvement of special forces, issuing a press release which made no mention of the SAS, but when it was made public that Brad Tinnion was a Lance Bombardier originally from 29 Commando Regiment Royal Artillery, it became clear to experts that Tinnion had been serving with special forces. Operation Barras was Tinnion's first operational deployment as an SAS trooper.Also confirmed to have died in the operation were 25 West Side Boys, although the true figure is probably far higher. The gang's resistance was stronger than had been expected and there was speculation that more bodies lay undiscovered in the jungle. Several other West Side Boys were captured, while others fled into the jungle. Many of those who fled later surrendered to Jordanian peacekeepers. The Jordanians had received 30 by the end of the day, and 371—including 57 children—had surrendered within a fortnight of Operation Barras, to which Julius Spencer, Sierra Leone's Minister for Information, declared that the West Side boys were "finished as a military threat". Some of those who surrendered went on to volunteer for the new Sierra Leone Army and those who were accepted went into the British-run training programme. Kallay, the gang's leader, recorded a message for broadcast on Sierra Leonean radio urging the remaining West Side Boys to surrender to UNAMSIL. He also identified the bodies of West Side Boys killed in Magbeni and Gberi Bana, which were subsequently buried in a mass grave.The morning of the operation, General Sir Charles Guthrie, Chief of the Defence Staff (CDS)—the professional head of the British Armed Forces—was coincidentally due to appear on Breakfast with Frost, a Sunday morning political television programme hosted by Sir David Frost. The first public knowledge of Operation Barras came from Guthrie's interview with Frost, which took place while the operation was still concluding. Guthrie told Frost "[W]e didn't want to have to assault, because it's a very difficult operation, there are big risks in it but we have done it [...] because our negotiations were getting nowhere. The hostages had been there  for three weeks, they [the West Side Boys] were threatening to kill them, or they were threatening to move them to other parts of Sierra Leone and once they'd done that we'd never be able to recover [the soldiers] with ease, which I hope we've done this morning". The MoD issued a press release with more details later in the day. 
Question: What is the last name of the person that conducted the interview telling the public of the operation that resulted in one British soldier death?
Output (English): Frost.