You will be given a definition of a task first, then some input of the task.
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.

Passage: The 6000-mark war was a war between Denmark and Sweden which took place from 1276 to 1278. It started because of a disagreement over an agreed sum of 6,000 silver marks for Danish assistance to Magnus Birgersson in the battle against Valdemar Birgersson in 1275.
Question: How many years did the 6000-mark war last?
Output:
number