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

    【Schema】
    【DB_ID】 hockey
【Schema】
# Table: Scoring
[
(playerID:TEXT, Examples: [aaltoan01, abbeybr01, abbotge01]),
(year:INTEGER, Examples: [1997, 1998, 1999]),
(stint:INTEGER, Examples: [1, 2, 3]),
(tmID:TEXT, Examples: [ANA, CIN, BOS]),
(lgID:TEXT, Examples: [NHL, WHA, PCHA]),
(pos:TEXT, Examples: [C, D, G]),
(GP:INTEGER, Examples: [3, 73, 63]),
(G:INTEGER, Examples: [0, 3, 7]),
(A:INTEGER, Examples: [0, 5, 11]),
(Pts:INTEGER, Examples: [0, 8, 18]),
(PIM:INTEGER, Examples: [0, 24, 26]),
(+/-:TEXT, Examples: [-1, -12, -13]),
(PPG:TEXT, Examples: [0, 2, 1]),
(PPA:TEXT, Examples: [0, 1, 2]),
(SHG:TEXT, Examples: [0, 2, 1]),
(SHA:TEXT, Examples: [0, 1, 2]),
(GWG:TEXT, Examples: [0, 1, 3]),
(GTG:TEXT, Examples: [0, 1, 3]),
(SOG:TEXT, Examples: [1, 61, 102]),
(PostGP:TEXT, Examples: [4, 10, 11]),
(PostG:TEXT, Examples: [0, 2, 1]),
(PostA:TEXT, Examples: [0, 1, 3]),
(PostPts:TEXT, Examples: [0, 3, 2]),
(PostPIM:TEXT, Examples: [2, 0, 36]),
(Post+/-:TEXT, Examples: [0, 2, 1]),
(PostPPG:TEXT, Examples: [0, 1, 5]),
(PostPPA:TEXT, Examples: [0, 1, 3]),
(PostSHG:TEXT, Examples: [0, 1, 2]),
(PostSHA:TEXT, Examples: [0, 1, 2]),
(PostGWG:TEXT, Examples: [0, 1, 2]),
(PostSOG:TEXT, Examples: [0, 11, 12])
]
# Table: SeriesPost
[
(year:INTEGER, Examples: [1912, 1913, 1914]),
(round:TEXT, Examples: [SCF, F, SF]),
(series:TEXT, Examples: [A, B, C]),
(tmIDWinner:TEXT, Examples: [VA1, TBS, OT1]),
(lgIDWinner:TEXT, Examples: [PCHA, NHA, NHL]),
(tmIDLoser:TEXT, Examples: [QU1, MOC, VA1]),
(lgIDLoser:TEXT, Examples: [NHA, PCHA, NHL]),
(W:INTEGER, Examples: [2, 1, 3]),
(L:INTEGER, Examples: [1, 0, 2]),
(T:INTEGER, Examples: [0, 1, 2]),
(GoalsWinner:INTEGER, Examples: [16, 6, 13]),
(GoalsLoser:INTEGER, Examples: [12, 2, 8]),
(note:TEXT, Examples: [EX, TG, ND])
]
# Table: TeamsPost
[
(year:INTEGER, Primary Key, Examples: [1913, 1914, 1916]),
(lgID:TEXT, Examples: [NHA, NHL, PCHA]),
(tmID:TEXT, Primary Key, Examples: [MOC, TBS, MOW]),
(G:INTEGER, Examples: [2, 5, 6]),
(W:INTEGER, Examples: [1, 0, 4]),
(L:INTEGER, Examples: [1, 0, 4]),
(T:INTEGER, Examples: [0, 1, 2]),
(GF:INTEGER, Examples: [2, 6, 1]),
(GA:INTEGER, Examples: [6, 2, 4]),
(PIM:TEXT, Examples: [59, 68, 87]),
(BenchMinor:TEXT, Examples: [0, 6, 2]),
(PPG:TEXT, Examples: [1, 5, 9]),
(PPC:TEXT, Examples: [39, 27, 25]),
(SHA:TEXT, Examples: [0, 1, 2]),
(PKG:TEXT, Examples: [3, 8, 4]),
(PKC:TEXT, Examples: [55, 45, 20]),
(SHF:TEXT, Examples: [0, 1, 3])
]
# Table: ScoringShootout
[
(playerID:TEXT, Examples: [adamske01, afanadm01, afinoma01]),
(year:INTEGER, Examples: [2006, 2005, 2007]),
(stint:INTEGER, Examples: [1, 2, 3]),
(tmID:TEXT, Examples: [PHO, TBL, BUF]),
(S:INTEGER, Examples: [1, 2, 5]),
(G:INTEGER, Examples: [0, 1, 3]),
(GDG:INTEGER, Examples: [0, 1, 2])
]
# Table: AwardsCoaches
[
(coachID:TEXT, Examples: [patrile01c, irvindi01c, gormato01c]),
(award:TEXT, Examples: [First Team All-Star, Second Team All-Star, Jack Adams]),
(year:INTEGER, Examples: [1930, 1931, 1932]),
(lgID:TEXT, Examples: [NHL, WHA]),
(note:TEXT)
]
# Table: AwardsMisc
[
(name:TEXT, Primary Key, Examples: [1960 U.S. Olympic Hockey Team]),
(ID:TEXT, Examples: [arboual01, delveal01, rossar01]),
(award:TEXT, Examples: [Patrick]),
(year:INTEGER, Examples: [2001, 1998, 1991]),
(lgID:TEXT, Examples: [NHL]),
(note:TEXT, Examples: [posthumous])
]
# Table: Master
[
(playerID:TEXT, Examples: [aaltoan01, abbeybr01, abbotge01]),
(coachID:TEXT, Examples: [abelsi01c, adamsja01c, agnewga01c]),
(hofID:TEXT, Examples: [abelsi01h, adamsch01h, adamsja01h]),
(firstName:TEXT, Examples: [Antti, Bruce, George]),
(lastName:TEXT, Examples: [Aalto, Abbey, Abbott]),
(nameNote:TEXT, Examples: [also known as Bellehumeur]),
(nameGiven:TEXT, Examples: [Antti, Bruce, George Henry]),
(nameNick:TEXT, Examples: [Preacher, Taffy, Boot Nose]),
(height:TEXT, Examples: [73, 67, 71]),
(weight:TEXT, Examples: [210, 185, 153]),
(shootCatch:TEXT, Examples: [L, R, B]),
(legendsID:TEXT, Examples: [14862, 18411, 11801]),
(ihdbID:TEXT, Examples: [5928, 11918, 14591]),
(hrefID:TEXT, Examples: [aaltoan01, abbeybr01, abbotge01]),
(firstNHL:TEXT, Examples: [1997, 1943, 1952]),
(lastNHL:TEXT, Examples: [2000, 1943, 1952]),
(firstWHA:TEXT, Examples: [1975, 1976, 1974]),
(lastWHA:TEXT, Examples: [1975, 1977, 1976]),
(pos:TEXT, Examples: [C, D, G]),
(birthYear:TEXT, Examples: [1975, 1951, 1911]),
(birthMon:TEXT, Examples: [3, 8, 2]),
(birthDay:TEXT, Examples: [4, 18, 3]),
(birthCountry:TEXT, Examples: [Finland, Canada, USA]),
(birthState:TEXT, Examples: [ON, MB, MI]),
(birthCity:TEXT, Examples: [Lappeenranta, Toronto, Synenham]),
(deathYear:TEXT, Examples: [1964, 2000, 2001]),
(deathMon:TEXT, Examples: [8, 2, 12]),
(deathDay:TEXT, Examples: [1, 7, 24]),
(deathCountry:TEXT, Examples: [USA, Canada, France]),
(deathState:TEXT, Examples: [MI, AB, SK]),
(deathCity:TEXT, Examples: [Sault Ste. Marie, Farmington, Calgary])
]
# Table: ScoringSC
[
(playerID:TEXT, Examples: [adamsbi01, adamsja01, anderer02]),
(year:INTEGER, Examples: [1920, 1921, 1923]),
(tmID:TEXT, Examples: [VML, CAT, VIC]),
(lgID:TEXT, Examples: [PCHA, WCHL, NHL]),
(pos:TEXT, Examples: [R, C, L]),
(GP:INTEGER, Examples: [4, 5, 2]),
(G:INTEGER, Examples: [0, 2, 6]),
(A:INTEGER, Examples: [0, 1, 2]),
(Pts:INTEGER, Examples: [0, 3, 7]),
(PIM:INTEGER, Examples: [0, 6, 18])
]
# Table: TeamsSC
[
(year:INTEGER, Primary Key, Examples: [1912, 1913, 1914]),
(lgID:TEXT, Examples: [NHA, PCHA, NHL]),
(tmID:TEXT, Primary Key, Examples: [QU1, VA1, TBS]),
(G:INTEGER, Examples: [3, 5, 4]),
(W:INTEGER, Examples: [1, 2, 3]),
(L:INTEGER, Examples: [2, 1, 0]),
(T:INTEGER, Examples: [0, 1]),
(GF:INTEGER, Examples: [12, 16, 13]),
(GA:INTEGER, Examples: [16, 12, 8]),
(PIM:TEXT, Examples: [24, 20, 75])
]
# Table: TeamSplits
[
(year:INTEGER, Primary Key, Examples: [1909, 1910, 1911]),
(lgID:TEXT, Examples: [NHA, PCHA, NHL]),
(tmID:TEXT, Primary Key, Examples: [COB, HAI, LES]),
(hW:INTEGER, Examples: [2, 3, 6]),
(hL:INTEGER, Examples: [4, 3, 2]),
(hT:INTEGER, Examples: [0, 1, 2]),
(hOTL:TEXT, Examples: [2, 3, 1]),
(rW:INTEGER, Examples: [2, 1, 0]),
(rL:INTEGER, Examples: [4, 5, 6]),
(rT:INTEGER, Examples: [0, 1, 2]),
(rOTL:TEXT, Examples: [1, 5, 3]),
(SepW:TEXT, Examples: [1]),
(SepL:TEXT, Examples: [1]),
(SepT:TEXT),
(SepOL:TEXT, Examples: [0]),
(OctW:TEXT, Examples: [0, 1, 2]),
(OctL:TEXT, Examples: [1, 0, 2]),
(OctT:TEXT, Examples: [0, 1, 4]),
(OctOL:TEXT, Examples: [1, 0, 2]),
(NovW:TEXT, Examples: [5, 1, 2]),
(NovL:TEXT, Examples: [1, 4, 3]),
(NovT:TEXT, Examples: [0, 1, 2]),
(NovOL:TEXT, Examples: [0, 2, 1]),
(DecW:TEXT, Examples: [0, 1, 2]),
(DecL:TEXT, Examples: [1, 0, 2]),
(DecT:TEXT, Examples: [0, 1, 2]),
(DecOL:TEXT, Examples: [0, 2, 1]),
(JanW:INTEGER, Examples: [1, 0, 2]),
(JanL:INTEGER, Examples: [1, 3, 2]),
(JanT:INTEGER, Examples: [0, 1, 3]),
(JanOL:TEXT, Examples: [0, 1, 2]),
(FebW:INTEGER, Examples: [2, 1, 6]),
(FebL:INTEGER, Examples: [3, 5, 0]),
(FebT:INTEGER, Examples: [0, 1, 2]),
(FebOL:TEXT, Examples: [0, 1, 4]),
(MarW:TEXT, Examples: [1, 3, 0]),
(MarL:TEXT, Examples: [4, 0, 2]),
(MarT:TEXT, Examples: [0, 1, 2]),
(MarOL:TEXT, Examples: [1, 0, 2]),
(AprW:TEXT, Examples: [1, 0, 2]),
(AprL:TEXT, Examples: [0, 2, 1]),
(AprT:TEXT, Examples: [0, 1, 2]),
(AprOL:TEXT, Examples: [1, 0, 2])
]
# Table: GoaliesSC
[
(playerID:TEXT, Primary Key, Examples: [benedcl01, clancki01, holmeha01]),
(year:INTEGER, Primary Key, Examples: [1914, 1919, 1920]),
(tmID:TEXT, Examples: [OT1, OTS, MTM]),
(lgID:TEXT, Examples: [NHA, NHL, PCHA]),
(GP:INTEGER, Examples: [3, 5, 6]),
(Min:INTEGER, Examples: [180, 300, 361]),
(W:INTEGER, Examples: [0, 3, 5]),
(L:INTEGER, Examples: [3, 2, 1]),
(T:INTEGER, Examples: [0, 1]),
(SHO:INTEGER, Examples: [0, 1, 3]),
(GA:INTEGER, Examples: [26, 11, 12])
]
# Table: CombinedShutouts
[
(year:INTEGER, Examples: [1929, 1941, 1955]),
(month:INTEGER, Examples: [3, 2, 11]),
(date:INTEGER, Examples: [14, 15, 22]),
(tmID:TEXT, Examples: [TOR, MTL, OAK]),
(oppID:TEXT, Examples: [NYA, BOS, PHI]),
(R/P:TEXT, Examples: [R, P]),
(IDgoalie1:TEXT, Examples: [chabolo01, bibeapa01, plantja01]),
(IDgoalie2:TEXT, Examples: [grantbe01, gardibe01, hodgech01])
]
# Table: GoaliesShootout
[
(playerID:TEXT, Examples: [aebisda01, andercr01, aubinje01]),
(year:INTEGER, Examples: [2005, 2006, 2008]),
(stint:INTEGER, Examples: [1, 2]),
(tmID:TEXT, Examples: [COL, MTL, CHI]),
(W:INTEGER, Examples: [2, 0, 1]),
(L:INTEGER, Examples: [1, 2, 3]),
(SA:INTEGER, Examples: [10, 18, 7]),
(GA:INTEGER, Examples: [2, 6, 5])
]
# Table: Teams
[
(year:INTEGER, Primary Key, Examples: [1909, 1910, 1911]),
(lgID:TEXT, Examples: [NHA, PCHA, NHL]),
(tmID:TEXT, Primary Key, Examples: [COB, HAI, LES]),
(franchID:TEXT, Examples: [BKN, MTL, TBS]),
(confID:TEXT, Examples: [CC, WA, WC]),
(divID:TEXT, Examples: [AM, CA, ED]),
(rank:INTEGER, Examples: [4, 5, 7]),
(playoff:TEXT, Examples: [LCS, WCS, NHAF]),
(G:INTEGER, Examples: [12, 16, 18]),
(W:INTEGER, Examples: [4, 2, 3]),
(L:INTEGER, Examples: [8, 10, 1]),
(T:INTEGER, Examples: [0, 1, 2]),
(OTL:TEXT, Examples: [3, 4, 6]),
(Pts:INTEGER, Examples: [8, 4, 7]),
(SoW:TEXT, Examples: [3, 5, 2]),
(SoL:TEXT, Examples: [7, 5, 8]),
(GF:INTEGER, Examples: [79, 77, 59]),
(GA:INTEGER, Examples: [104, 83, 100]),
(name:TEXT, Examples: [Cobalt Silver Kings]),
(PIM:TEXT, Examples: [336, 27, 333]),
(BenchMinor:TEXT, Examples: [12, 14, 8]),
(PPG:TEXT, Examples: [28, 51, 42]),
(PPC:TEXT, Examples: [220, 279, 240]),
(SHA:TEXT, Examples: [4, 2, 5]),
(PKG:TEXT, Examples: [45, 43, 36]),
(PKC:TEXT, Examples: [242, 301, 267]),
(SHF:TEXT, Examples: [3, 8, 2])
]
# Table: TeamsHalf
[
(year:INTEGER, Primary Key, Examples: [1916, 1917, 1918]),
(lgID:TEXT, Examples: [NHA, NHL]),
(tmID:TEXT, Primary Key, Examples: [MOC, MOW, OT1]),
(half:INTEGER, Primary Key, Examples: [1, 2]),
(rank:INTEGER, Examples: [1, 3, 5]),
(G:INTEGER, Examples: [10, 4, 14]),
(W:INTEGER, Examples: [7, 3, 2]),
(L:INTEGER, Examples: [3, 7, 8]),
(T:INTEGER, Examples: [0]),
(GF:INTEGER, Examples: [58, 31, 56]),
(GA:INTEGER, Examples: [38, 42, 72])
]
# Table: Goalies
[
(playerID:TEXT, Primary Key, Examples: [abbotge01, abrahch01, adamsjo02]),
(year:INTEGER, Primary Key, Examples: [1943, 1974, 1975]),
(stint:INTEGER, Primary Key, Examples: [1, 2, 3]),
(tmID:TEXT, Examples: [BOS, NEW, WAS]),
(lgID:TEXT, Examples: [NHL, WHA, NHA]),
(GP:TEXT, Examples: [1, 16, 41]),
(Min:TEXT, Examples: [60, 870, 2385]),
(W:TEXT, Examples: [0, 8, 18]),
(L:TEXT, Examples: [1, 6, 18]),
(T/OL:TEXT, Examples: [0, 1, 2]),
(ENG:TEXT, Examples: [0, 1, 3]),
(SHO:TEXT, Examples: [0, 1, 2]),
(GA:TEXT, Examples: [7, 47, 136]),
(SA:TEXT, Examples: [504, 1221, 1438]),
(PostGP:TEXT, Examples: [1, 2, 11]),
(PostMin:TEXT, Examples: [1, 90, 34]),
(PostW:TEXT, Examples: [0, 6, 1]),
(PostL:TEXT, Examples: [0, 1, 5]),
(PostT:TEXT, Examples: [1, 0, 2]),
(PostENG:TEXT, Examples: [0, 1, 2]),
(PostSHO:TEXT, Examples: [0, 1, 2]),
(PostGA:TEXT, Examples: [0, 5, 1]),
(PostSA:TEXT, Examples: [51, 0, 14])
]
# Table: abbrev
[
(Type:TEXT, Primary Key, Examples: [Conference, Division, Playoffs]),
(Code:TEXT, Primary Key, Examples: [CC, EC, WA]),
(Fullname:TEXT, Examples: [Campbell Conference, Eastern Conference, Wales Conference])
]
# Table: Coaches
[
(coachID:TEXT, Primary Key, Examples: [abelsi01c, adamsja01c, agnewga01c]),
(year:INTEGER, Primary Key, Examples: [1952, 1953, 1957]),
(tmID:TEXT, Primary Key, Examples: [CHI, DET, STL]),
(lgID:TEXT, Examples: [NHL, WHA, NHA]),
(stint:INTEGER, Primary Key, Examples: [1, 2, 3]),
(notes:TEXT, Examples: [interim]),
(g:INTEGER, Examples: [70, 33, 74]),
(w:INTEGER, Examples: [27, 12, 16]),
(l:INTEGER, Examples: [28, 51, 12]),
(t:INTEGER, Examples: [15, 7, 5]),
(postg:TEXT, Examples: [7, 4, 6]),
(postw:TEXT, Examples: [3, 0, 2]),
(postl:TEXT, Examples: [4, 5, 6]),
(postt:TEXT, Examples: [0, 1, 2])
]
# Table: TeamVsTeam
[
(year:INTEGER, Primary Key, Examples: [1909, 1910, 1911]),
(lgID:TEXT, Examples: [NHA, PCHA, NHL]),
(tmID:TEXT, Primary Key, Examples: [COB, HAI, LES]),
(oppID:TEXT, Primary Key, Examples: [HAI, LES, MOS]),
(W:INTEGER, Examples: [1, 2, 0]),
(L:INTEGER, Examples: [1, 0, 2]),
(T:INTEGER, Examples: [0, 1, 2]),
(OTL:TEXT, Examples: [0, 1, 3])
]
# Table: ScoringSup
[
(playerID:TEXT, Examples: [actonke01, adamsgr01, allismi01]),
(year:INTEGER, Examples: [1988, 1989, 1987]),
(PPA:TEXT, Examples: [1, 5, 4]),
(SHA:TEXT, Examples: [1, 2, 4])
]
# Table: HOF
[
(year:INTEGER, Examples: [1969, 1960, 1959]),
(hofID:TEXT, Primary Key, Examples: [abelsi01h, adamsch01h, adamsja01h]),
(name:TEXT, Examples: [Sid Abel, Charles Adams, Jack Adams]),
(category:TEXT, Examples: [Player, Builder, Referee/Linesman])
]
# Table: AwardsPlayers
[
(playerID:TEXT, Primary Key, Examples: [abelsi01, alfreda01, amontto01]),
(award:TEXT, Primary Key, Examples: [First Team All-Star, Hart, Second Team All-Star]),
(year:INTEGER, Primary Key, Examples: [1948, 1949, 1941]),
(lgID:TEXT, Examples: [NHL, WHA]),
(note:TEXT, Examples: [tie, shared, Most Gentlemanly]),
(pos:TEXT, Examples: [C, LW, F])
]
【Foreign keys】
Scoring.year=Teams.year
Scoring.tmID=Teams.tmID
Scoring.playerID=Master.playerID
SeriesPost.year=Teams.year
SeriesPost.tmIDWinner=Teams.tmID
SeriesPost.year=Teams.year
SeriesPost.tmIDLoser=Teams.tmID
TeamsPost.year=Teams.year
TeamsPost.tmID=Teams.tmID
ScoringShootout.year=Teams.year
ScoringShootout.tmID=Teams.tmID
ScoringShootout.playerID=Master.playerID
AwardsCoaches.coachID=Coaches.coachID
Master.coachID=Coaches.coachID
ScoringSC.year=Teams.year
ScoringSC.tmID=Teams.tmID
ScoringSC.playerID=Master.playerID
TeamsSC.year=Teams.year
TeamsSC.tmID=Teams.tmID
TeamSplits.year=Teams.year
TeamSplits.tmID=Teams.tmID
GoaliesSC.year=Teams.year
GoaliesSC.tmID=Teams.tmID
GoaliesSC.playerID=Master.playerID
CombinedShutouts.IDgoalie1=Master.playerID
CombinedShutouts.IDgoalie2=Master.playerID
GoaliesShootout.year=Teams.year
GoaliesShootout.tmID=Teams.tmID
GoaliesShootout.playerID=Master.playerID
TeamsHalf.tmID=Teams.tmID
TeamsHalf.year=Teams.year
Goalies.year=Teams.year
Goalies.tmID=Teams.tmID
Goalies.playerID=Master.playerID
Coaches.year=Teams.year
Coaches.tmID=Teams.tmID
TeamVsTeam.year=Teams.year
TeamVsTeam.tmID=Teams.tmID
TeamVsTeam.oppID=Teams.tmID
TeamVsTeam.year=Teams.year
ScoringSup.playerID=Master.playerID
AwardsPlayers.playerID=Master.playerID

    【Question】
    How many former athletes go on to become coaches after retiring?

    【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(playerID) FROM Master WHERE playerID IS NOT NULL AND coachID IS NOT NULL