You will be given a definition of a task first, then some input of the task.
Given a context passage, generate a question from the passage such that its answer is shortest continous span from the 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.
Output:
What was Magnus Birgersson supposed to have been paid for?