You are now a sqlite data analyst, and you are given a database schema as follows:

    【Schema】
    【DB_ID】 book_publishing_company
【Schema】
# Table: titleauthor
[
(au_id:TEXT, Primary Key, Examples: [172-32-1176, 213-46-8915, 238-95-7766]),
(title_id:TEXT, Primary Key, Examples: [PS3333, BU1032, BU2075]),
(au_ord:INTEGER, Examples: [1, 2, 3]),
(royaltyper:INTEGER, Examples: [100, 40, 30])
]
# Table: roysched
[
(title_id:TEXT, Examples: [BU1032, PC1035, BU2075]),
(lorange:INTEGER, Examples: [0, 5001, 2001]),
(hirange:INTEGER, Examples: [5000, 50000, 2000]),
(royalty:INTEGER, Examples: [10, 12, 14])
]
# Table: titles
[
(title_id:TEXT, Primary Key, Examples: [BU1032, BU1111, BU2075]),
(title:TEXT),
(type:TEXT, Examples: [business, mod_cook, UNDECIDED]),
(pub_id:TEXT, Examples: [1389, 0736, 0877]),
(price:REAL, Examples: [19.99, 11.95, 2.99]),
(advance:REAL, Examples: [5000.0, 10125.0, 0.0]),
(royalty:INTEGER, Examples: [10, 24, 12]),
(ytd_sales:INTEGER, Examples: [4095, 3876, 18722]),
(notes:TEXT),
(pubdate:DATETIME, Examples: [1991-06-12 00:00:00])
]
# Table: employee
[
(emp_id:TEXT, Primary Key, Examples: [A-C71970F, A-R89858F, AMD15433F]),
(fname:TEXT, Examples: [Aria, Annette, Ann]),
(minit:TEXT, Examples: [M, R, F]),
(lname:TEXT, Examples: [Cruz, Roulet, Devon]),
(job_id:INTEGER, Examples: [10, 6, 3]),
(job_lvl:INTEGER, Examples: [87, 152, 200]),
(pub_id:TEXT, Examples: [1389, 9999, 9952]),
(hire_date:DATETIME, Examples: [1991-10-26 00:00:00])
]
# Table: authors
[
(au_id:TEXT, Primary Key, Examples: [172-32-1176, 213-46-8915, 238-95-7766]),
(au_lname:TEXT, Examples: [White, Green, Carson]),
(au_fname:TEXT, Examples: [Johnson, Marjorie, Cheryl]),
(phone:TEXT, Examples: [408 496-7223, 415 986-7020, 415 548-7723]),
(address:TEXT, Examples: [10932 Bigge Rd., 309 63rd St. #411, 589 Darwin Ln.]),
(city:TEXT, Examples: [Menlo Park, Oakland, Berkeley]),
(state:TEXT, Examples: [CA, KS, TN]),
(zip:TEXT, Examples: [94025, 94618, 94705]),
(contract:TEXT, Examples: [0])
]
# Table: sales
[
(stor_id:TEXT, Primary Key, Examples: [6380, 7066, 7067]),
(ord_num:TEXT, Primary Key, Examples: [6871, 722a, A2976]),
(ord_date:DATETIME, Examples: [1994-09-14 00:00:00]),
(qty:INTEGER, Examples: [5, 3, 50]),
(payterms:TEXT, Examples: [Net 60, Net 30, ON invoice]),
(title_id:TEXT, Primary Key, Examples: [BU1032, PS2091, PC8888])
]
# Table: jobs
[
(job_id:INTEGER, Primary Key, Examples: [1, 2, 3]),
(job_desc:TEXT, Examples: [New Hire - Job not specified]),
(min_lvl:INTEGER, Examples: [10, 200, 175]),
(max_lvl:INTEGER, Examples: [10, 250, 225])
]
# Table: publishers
[
(pub_id:TEXT, Primary Key, Examples: [0736, 0877, 1389]),
(pub_name:TEXT, Examples: [New Moon Books, Binnet & Hardley, Algodata Infosystems]),
(city:TEXT, Examples: [Boston, Washington, Berkeley]),
(state:TEXT, Examples: [MA, DC, CA]),
(country:TEXT, Examples: [USA, Germany, France])
]
# Table: discounts
[
(discounttype:TEXT, Examples: [Initial Customer, Volume Discount, Customer Discount]),
(stor_id:TEXT, Examples: [8042]),
(lowqty:INTEGER, Examples: [100]),
(highqty:INTEGER, Examples: [1000]),
(discount:REAL, Examples: [10.5, 6.7, 5.0])
]
# Table: stores
[
(stor_id:TEXT, Primary Key, Examples: [6380, 7066, 7067]),
(stor_name:TEXT, Examples: [Eric the Read Books, Barnum's, News & Brews]),
(stor_address:TEXT, Examples: [788 Catamaugus Ave., 567 Pasadena Ave., 577 First St.]),
(city:TEXT, Examples: [Seattle, Tustin, Los Gatos]),
(state:TEXT, Examples: [WA, CA, OR]),
(zip:TEXT, Examples: [98056, 92789, 96745])
]
# Table: pub_info
[
(pub_id:TEXT, Primary Key, Examples: [0877, 1389, 1622]),
(logo:BLOB),
(pr_info:TEXT)
]
【Foreign keys】
titleauthor.au_id=authors.au_id
titleauthor.title_id=titles.title_id
roysched.title_id=titles.title_id
titles.pub_id=publishers.pub_id
employee.job_id=jobs.job_id
employee.pub_id=publishers.pub_id
sales.stor_id=stores.stor_id
sales.title_id=titles.title_id
discounts.stor_id=stores.stor_id
pub_info.pub_id=publishers.pub_id

    【Question】
    How many publishers are in the USA?

    【Evidence】
    

    Please read and understand the database schema carefully, and generate an executable SQL based on the user's question and evidence. 

SQL: SELECT COUNT(pub_id) FROM publishers WHERE country = 'USA'