Carlos Torres' company wants to establish an assembly line to manufacture its new product, the iStar phone. Carlos' goal is to produce $60$ iStars per hour. Tasks, task times, and immediate predecessors are as follows:

$\backslash$table$[[$Task$,\backslash$table$[[$Performance$],[$Time $($seconds$)]],$Predecessors,Task,$\backslash$table$[[$Performance$],[$Time $($seconds$)]],$Predecessors$],[$A$,50,-,$F$,26,$C$],[$B$,30,$A$,$G$,16,$C$],[$C$,52,$A$,$H$,21,$D$,$ E$],[$D$,41,$B$,$I,$18,$F$,$ G$],[$E$,8,$B$,$J$,50,$H$,$ I$]]$

a$)$ The theoretical minimum number of workstations that Carlos can achieve in the assembly line $=($round your response to the immediate higher whole number$).$