Given a passage and a question, find the answer to the question based on the passage. The answer should consist of only one word that lies in the span of only one of the sentences in the passage.

Ex Input:
Paragraph: Armed conflict began in 1775 . In 1776 , the Second Continental Congress declared the independence of the colonies as the United States of America . Led by General George Washington , it won the Revolutionary War with large support from France . The peace treaty of 1783 gave the new nation the land east of the Mississippi River ( except Canada and Florida ) . The Articles of Confederation established a central government , but it was ineffectual at providing stability , as it could not collect taxes and had no executive officer . A convention in 1787 wrote a new Constitution that was adopted in 1789 . In 1791 , a Bill of Rights was added to guarantee inalienable rights . With Washington as the first president and Alexander Hamilton his chief adviser , a strong central government was created . Purchase of the Louisiana Territory from France in 1803 doubled the size of the United States . A second and final war with Britain was fought in 1812 , which solidified national pride .
Question: when did we become the united states of america


Ex Output:
1776


Ex Input:
Paragraph: The periodic table is a tabular arrangement of the chemical elements , ordered by their atomic number , electron configuration , and recurring chemical properties , whose adopted structure shows periodic trends . Generally , within one row ( period ) the elements are metals on the left , and non-metals on the right , with the elements having similar chemical behaviours being placed in the same column . Table rows are commonly called periods and columns are called groups . Six groups have accepted names as well as assigned numbers : for example , group 17 elements are halogens ; and group 18 are noble gases . Also displayed are four simple rectangular areas or blocks associated with the filling of different atomic orbitals .
Question: what is the name given to the rows in the periodic table


Ex Output:
periods


Ex Input:
Paragraph: To comply with the new requirements and to manage the increased liability load , the organizers formed Black Rock City , LLC . Will Roger Peterson and Flynn Mauthe created the Department of Public Works ( DPW ) to build the `` city '' grid layout ( a requirement so that emergency vehicles could be directed to an `` address '' ) designed by Rod Garrett , an architect . Rod continued as the city designer until his death , in 2011 , at the age of 76 . He is also credited with the design of all of the man bases from 2001 through 2012 , the center camp cafe and first camp . With the success of the driving ban , having no vehicular incidents , 1998 saw a return to the Black Rock desert , along with a temporary perimeter fence . The event has remained there since .
Question: when did burning man move to black rock city


Ex Output:

1998