public class ParaT2023$2023$ extends RecursiveTask {$\{$

int lo,$,$ hi,$,$ val;

int[]$[]$ arr;

static final int CUT=5$=5$;

ParaT2023($2023($int[]$[]$ a,$,$ int l,$,$ int h,$,$ int v){$)\{$ lo=$=$l; hi=$=$h; arr=$=$a; val=$=$v;}$\}$

protected Integer compute(){$()\{$

if(($(($hi−$-$lo)<$)<$ CUT){$)\{$

int ans =−1$=-1$;

for($($int i=($=($lo+1)$+1)$; i <$<$ hi; i++){$++)\{$

if ($($ arr[$[$i]==$]==$val)$)$ ans=$=$i;

}$\}$

return ans;

}$\}$

else {$\{$

ParaT2023$2023$ left =$=$ new ParaT2023($2023($arr,$,$lo,($,($hi+$+$lo)/2,$)/2,$val)$)$;

ParaT2023$2023$ right=$=$ new ParaT2023($2023($arr,($,($hi+$+$lo)/2,$)/2,$hi,$,$val)$)$;

left.fork()$()$;

int rightAns =$=$ right.compute()$()$;

int leftAns =$=$ left.join()$()$;

if ($($rightAns>−1)$>-1)$ return rightAns;

return leftAns;

}}$\}\}$

public static void main($($String[]$[]$ args)$)$ throws Exception {$\{$

int []$[]$ arr ={0,1,2,3,4,5,0,7,8,0,10,11,12,13,14,15,0,17,18,19,20}$=\{0,1,2,3,4,5,0,7,8,0,10,11,12,13,14,15,0,17,18,19,20\}$;

final ForkJoinPool fjPool =$=$ ForkJoinPool.commonPool()$()$;

int ans =$=$ fjPool.invoke($($new ParaT2023($2023($arr,0,$,0,$arr.length,0))$0))$;

System.out.println($($ans)$)$;

}}//$\}\}//$ How would i determine the number of threads used to execute this code which is apparently 4,$4,$ and how would i determine the output if it is 16.$16.$