Teacher:This task involves annotating the answer type to a given question that involve some kind of complex reasoning (including numerical reasoning). Note that the questions require looking at more than one part of the passage to answer. There are 3 possible answer types (i) spans, (ii) numbers and (iii) dates. If the answer can be found in the passage, label it as "span". If the answer is a number, label as "number". Similarly, label "date" if you think the answer to the given question is a date.
Teacher: Now, understand the problem? Solve this instance: Passage: 1st Squadron, 10th Cavalry with the 4th Infantry Division participated in Exercise Reforger in 1977, 1978, 1981, 1985, 1987, and 1991. Exercise Reforger was an annual exercise conducted, during the Cold War, by NATO. The exercise was intended to ensure that NATO had the ability to quickly deploy forces to West Germany in the event of a conflict with the Warsaw Pact. 2nd Squadron, 10th Cavalry with the 7th Infantry Division participated in Exercise Reforger in 1984, 1986 and 1993. 3rd Battalion, 10th Cavalry was activated in the 1st Cavalry Division at Fort Hood, Texas, in 1977.
Question: What was the first year that Exercise Reforger took place?
Student:
date