Question: How many books were written by the historian that remarked on Didius's treachery? Passage 1:Robert Bliss was involved with many cultural and civic organizations. He served as honorary president and trustee of the American Federation of Arts; president of the American Foreign Service Association; vice-chairman of the Smithsonian Art Commission; vice-chairman of the board of the National Trust for Historic Preservation; director and first vice-president of the Washington Criminal Justice Association; member of the American Academy of Political and Social Science; and member of the Harvard Board of Overseers. He was trustee of the American Museum of Natural History, New York; trustee and executive committee member of the Carnegie Institution, Washington, D.C.; trustee of Nelson Rockefeller's Museum of Primitive Art, New York; trustee of the Santa Barbara Museum of Art; and member of the Advisory Committee on Art of the State Department's Division of Cultural Relations and the Office of the Coordinator of Inter-American Affairs. He received honorary Doctor of Law degrees from the University of Missouri (1933); Syracuse University (1934); and Harvard University (1951). Robert Bliss was one of five retired diplomats who co-signed a 1954 letter protesting U.S. Senator Joseph McCarthy's attacks on the Foreign Service.
 Passage 2:After his term as consul, Didius was assigned to govern the province of Hispania Citerior, where he served from 97 BC to 93 BC. Nearly his entire proconsular term in Spain was spent at war with the Celtiberi. In the four years Didius governed Spain he achieved multiple victories and is said to have slain 20,000 Arevaci, quelled the rebellious city of Termes (today Tiermes in the province of Soria), and besieged Colenda for nine months, after which time the city fell and the women and children were sold into slavery. Didius earned another triumph after slaughtering a colony of "robbers" -- in actuality, poor people who had banded together to subsist through banditry after losing their property. Didius lured them in with promises of land to live on, and when the families assembled within the Roman castra in good faith, he had them all killed. The historian Appian indicates that Didius's exceptional cruelty and treachery caused an even greater uprising which his experienced successor, C. Valerius Flaccus, had to put down.
 Passage 3:Peru – country located in western South America, on the Pacific Coast, north of Chile. Peruvian territory was home to several ancient cultures. Ranging from the Norte Chico civilization in the 32nd century BC, the oldest civilization in the Americas and one of the five cradles of civilization, to the Inca Empire, the largest state in pre-Columbian America, the territory now including Peru has one of the longest histories of civilization of any country, tracing its heritage back to the 4th millennia BCE. The Spanish Empire conquered the region in the 16th century and established a Viceroyalty, which included most of its South American colonies. After achieving independence in 1821, Peru has undergone periods of political unrest and fiscal crisis as well as periods of stability and economic upswing.

Output: 2