Instructions: 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'.
Input: Passage: At the beginning of the 13th century, a Prussian trade route developed that crossed over an isthmus between two large lakes, the Sicieńskie lake and the Zamkowe ("Castle lake"). A defensive wall was built at this spot, and later, a settlement was constructed there as well. The place is mentioned in a twelfth-century document regarding a battle in which Henry of Sandomierz was killed. Under the name "Wambresia" the town was mentioned in a 1251 Prussian Document issued at Chełmża. Bishop Heidenreich of Bishopric of Chełmno received the Chełmno Land from the pope. The Polish duke Konrad I of Masovia turned possession of the settlement over to the bishop of Chełmno. This created a problem because the Teutonic Knights were in control of the Chełmno Land, and a dispute began between the Bishop of Chełmno and the Knights. The Pope at the time, Innocent IV, was not keen to continue the dispute and installed the Bishop as the rightful ruler of the settlement. This disagreement was the first historical mention of the settlement. In 1251, a large church, St. Simon and Judah, was built in the city.
 Link Information: The Pope at the time, Innocent IV, was not keen to continue the dispute and installed the Bishop as the rightful ruler of the settlement. Question: Bishop Heidenreich received the Chelmno Land from a pope whose reign began when?
Output:
Answer: 25 June 1243 