What is the minimum cost of crashing the following project at Sawaya Robotics by $4$ days?

$\backslash$table$[[$ACTIVITY$,\backslash$table$[[$NORMAL$],[$TIME$],[($DAYS$)]],\backslash$table$[[$CRASH$],[$TIME$],[($DAYS$)]],\backslash$table$[[$NORMAL$],[$COST$]],\backslash$table$[[$CRASH$],[$COST$]],\backslash$table$[[$IMMEDIATE$],[$PREDECESSOR$($S$)]]],[$Design$,6,5,900,1,000,-],[$Wiring$,8,6,300,400,-],[\backslash$table$[[$Chip$],[$install$]],4,3,500,600,-],[$Software$,5,3,900,1,200,$A$,$ B$],[$Testing$,8,5,1,000,1,600,$C$]]$