In this task, you're given a passage, further information available on a particular linked term from the statement, and a question. Your job is to generate the answer to the question by using the information provided. If there is no clear answer obtainable, output 'none'.
Example: Passage: The group was occasionally diverted from strategic missions to carry out air support and interdiction missions. It supported Operation Overlord, the invasion of Normandy by attacking transportation targets, including bridges, along with airfields and strong points in France. On D Day, the squadron and the rest of the 446th Group led the first heavy bomber mission of the day. The 446th aided ground forces at Caen and Saint-Lo during July by hitting bridges, gun batteries, and enemy troops. During Operation Market Garden, the attempt to seize a bridgehead across the Rhine in the Netherlands, the 704th dropped supplies to allied troops near Nijmegen. It struck lines of communications during the Battle of the Bulge. During Operation Varsity in March 1945, it supplied ground and airborne troops near Wesel. The squadron flew its last combat mission on 25 April 1945 against Salzburg, Austria. The group had flown 273 missions and had lost 58 aircraft during the war,
. Link Information: Operation Market Garden was a failed World War II military operation fought in the Netherlands from 17 to 25 September 1944. Question: When did the operation during which the 704th dropped supplies to allied troops near Nijmegen begin?
Example solution: from 17 to 25 September 1944
Example explanation: The passage describes the 704th's actions during Operation Market Garden, and the answer specifies when the operation happened.

Problem: Passage: John H. Mercer was the third child of Harriet and John W. Mercer. He was educated at private schools in Cheltenham and, later, at Gordonstoun in Scotland. During World War II he served in the British Merchant Marines (194046) as a radio man. After the war he went to University of Cambridge and studied geography. At that time he came under the influence of William Vaughan Lewis. After finishing his B.A. in 1949 Mercer went to Canada, where he received his PhD in geography from McGill University in 1954. He was a Research Scholar from 1954 to 1956 at the Australian National University in Canberra, where he studied land use and population in western Samoa. He returned to Canada and worked in the Canadian Hydro-graphic Office in Ottawa as a geographer in 1957 and 1958. During 195960, 196162, 1964, and 1966, the American Geographical Society employed him at its World Data Center A for Glaciology in New York. The turning point in his career as a glaciologist was in 1960, when he became a Research Associate at The Ohio State University, in the Institute of Polar Studies (renamed the Byrd Polar Research Center). He remained at The Ohio State University until his death, becoming its first Senior Research Scientist.
Link Information: none Question: Who was the headmaster of Gordonstoun at that time?
Solution: Answer: none