Question: Which chain currently has more stores, Pietro's Pizza or Pizzeria Venti?
Context: Cassano's Pizza King, currently operating under the brand Cassano's, is a pizzeria chain based in Kettering, Ohio, a suburb of Dayton.  Established on June 4, 1953, by the Kettering grocer Victor "Vic" J. Cassano, Sr. (June 4, 1922 – January 1, 2002) and his mother-in-law Caroline "Mom" Donisi, the company currently (2005) operates 34 Cassano's Pizza King restaurants in the Dayton area, and has three other western Ohio franchises (in Russells Point, Fairfield and Sidney), plus a franchise in Quincy, Illinois, and another in Hannibal, Missouri.  The company also operates dozens of Cassano's Pizza Express kiosks in gas stations, convenience stores and hotels, and sells frozen pizza dough under the name Cassano's Fresh Frozen Dough Company. Pizza My Heart is a chain of pizzeria restaurants in the San Francisco Bay Area.  The chain was founded in 1981 in Capitola, California by Fred Poulos and Keith Holtaway and is now owned by Chuck Hammers.  The chain currently has eighteen locations.  In 1997, the chain merged with Pizza-a-Go-Go, which was based in San Jose, California.  The new locations inherited the Pizza My Heart name. Pizza Land is an independently owned pizzeria located at 260 Belleville Turnpike in North Arlington, New Jersey, which featured in the opening credits of "The Sopranos".  Additionally, in "Law & Order" episode 10.6, "Marathon" (1999), a pizza box from the restaurant was used by a suspect to transport and conceal firearms.  The pizzeria was opened in 1965 by Italian immigrant Frank Di Piazza, who died in 1991.  The pizzeria was built by Pietro Di Piazza.  It was owned by Frank's son Tony Di Piazza .  Tony and Debra Hunkele always had the pizzeria packed but later on sold to pizza maker Al Pawlowicz until his death in 2010, who purchased the restaurant from DiPiazza's son.  The store is now owned by Eddie Twdroos. Pizzeria Venti is a Tennessee-based company of franchised sit-down Italian restaurants featuring up to 20 different pizzas by the slice and Trattoria style Italian food.  It was founded in 2003 and has locations in 10 states throughout the United States. Venti is a network storage system that permanently stores data blocks.  A 160-bit SHA-1 hash of the data (called "score" by Venti) acts as the address of the data.  This enforces a "write-once" policy since no other data block can be found with the same address: the addresses of multiple writes of the same data are identical, so duplicate data is easily identified and the data block is stored only once.  Data blocks cannot be removed, making it ideal for permanent or backup storage.  Venti is typically used with Fossil to provide a file system with permanent snapshots. Rabbe Anders Grönblom (May 3, 1950 Helsinki, Finland – June 29, 2015) was a Finland-Swedish businessman who started a successful pizza business in Vaasa, Finland.  His first company—a pizzeria—was called "O sole mio" and it was founded in 1976 in the center of Vaasa.  From there he expanded to a pizza franchise chain first called "Pizzeria N:o 1".  He was known as the "Pizza-emperor" (Pizzakeisari in Finnish), because he was the founder of a well known pizza franchise chain called Kotipizza which was the new name of "Pizzeria N:o 1" which expanded fast outside of Vaasa.  The chain is said to be the biggest one in the Nordic countries.  He was also the founder of a shipping company called RG Line, a hotel chain called Omenahotelli and another pizza chain called Golden Rax Pizzabuffet.  Most of his companies are subsidiaries of Grönblom International LTD, where Rabbe Grönblom acted as director.  Golden Rax Pizzabuffet however is nowadays a part of Finland's largest hotel & restaurant company Restel Oy Ltd, where Rabbe Grönblom sat on the board.  He was also on the board of the Finnish tyre company Nokian Renkaat (since 2003). Uno Pizzeria & Grill (formerly Pizzeria Uno and Uno Chicago Grill), or more informally as Unos, is a franchised pizzeria restaurant chain under the parent company Uno Restaurant Holdings Corporation.  Uno Pizzeria and Grill is best known for its Chicago-style deep dish pizza.  Ike Sewell opened the first Pizzeria Uno in 1943. Pizza delivery is a service in which a pizzeria or pizza chain delivers a pizza to a customer.  An order is typically made either by telephone or over the internet to the pizza chain, in which the customer can request pizza type, size and other products alongside the pizza, commonly including soft drinks.  Pizzas may be delivered in pizza boxes or delivery bags, and deliveries are made with either an automobile, motorized scooter, or bicycle.  Customers can, depending on the pizza chain, choose to pay online, or in person, with cash, credit or a debit card.  A delivery fee is often charged with what the customer has bought. Pietro's Pizza is a small pizza chain in the U.S. state of Oregon.  Founded in 1957, the chain grew to about 80 restaurants and changed owners several times before shrinking to only four stores.  The company is based in Milwaukie, Oregon. Shakey's Pizza is a pizza restaurant chain based in the United States.  Founded in 1954, it was the first franchise pizza chain in the United States.  The chain currently has about 500 stores globally, and about 60 in the United States.
Answer: Pizzeria Venti