How do I remove the "Exception in thread "main" java.lang.NumberFormatException:" from the main output:

Test $1$: failure Expected$\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$ Enter sequence of integers, each followed by a space: Error: Invalid character $\text{'}$x$\text{'}$ found at index $0$ in input stream. Received$\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$ Enter sequence of integers, each followed by a space: Exception in thread "main" java.lang.NumberFormatException: Invalid character $\text{'}$x$\text{'}$ found at index $0$ in input stream. at InversionCounter.readArrayFromStdin$($InversionCounter$.$java:$103)$ at InversionCounter.main$($InversionCounter$.$java:$130)$ Expected length: $117,$ received length: $290$ Test $2$: failure Expected$\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$ Enter sequence of integers, each followed by a space: Error: Invalid character $\text{'}$x$\text{'}$ found at index $4$ in input stream. Received$\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$ Enter sequence of integers, each followed by a space: Exception in thread "main" java.lang.NumberFormatException: Invalid character $\text{'}$x$\text{'}$ found at index $4$ in input stream. at InversionCounter.readArrayFromStdin$($InversionCounter$.$java:$103)$ at InversionCounter.main$($InversionCounter$.$java:$130)$

private static int$[]$ readArrayFromStdin$()$ throws IOException,

NumberFormatException $\{$

List intList $=$ new LinkedList$<>()$;

BufferedReader reader $=$ new BufferedReader$($

new InputStreamReader$($System$.$in$))$;

int value $=0,$ index $=0,$ ch;

boolean valueFound $=$ false;

while $(($ch $=$ reader.read$())!=-1)\{$

if $($ch $>=\text{'}0\text{'}$ && ch $<=\text{'}9\text{'})\{$

valueFound $=$ true;

value $=$ value $*10+($ch $-48)$;

$\}$ else if $($ch $==\text{'}\text{'}||$ ch $==\text{'}$

$\text{'}||$ ch $==\text{'}\backslash$r$\text{'})\{$

if $($valueFound$)\{$

intList.add$($value$)$;

value $=0$;

$\}$

valueFound $=$ false;

if $($ch $!=\text{'}\text{'})\{$

break;

$\}$

$\}$ else $\{$

throw new NumberFormatException$($

"Invalid character $\text{'}"+($char$)$ch $+$

$"\text{'}$ found at index $"+$ index $+"$ in input stream."$)$;

$\}$

index$++$;

$\}$

int$[]$ array $=$ new int$[$intList$.$size$()]$;

Iterator iterator $=$ intList.iterator$()$;

index $=0$;

while $($iterator$.$hasNext$())\{$

array$[$index$++]=$ iterator.next$()$;

$\}$

return array;

$\}$

public static void main$($String$[]$ args$)$ throws IOException, NumberFormatException $\{$

if $($args$.$length $>1)\{$

System.out.println$("$Usage: java InversionCounter $[$slow$]")$;

System.exit$(1)$;

$\}$

if $($args$.$length $==1$ && $!$args$[0].$equals$("$slow$"))\{$

System.out.println$("$Error: Unrecognized option $\text{'}"+$ args$[0]+"\text{'}.")$;

System.exit$(1)$;

$\}$

System.out.print$("$Enter sequence of integers, each followed by a space: $")$;

int$[]$ array $=$ readArrayFromStdin$()$;;

if $($array$.$length $==0)\{$

System.out.println$("$Error: Sequence of integers not received."$)$;

System.exit$(1)$;

$\}$

if $($args$.$length $==1$ && args$[0].$equals$("$slow$"))\{$

System.out.println$("$Number of inversions: $"+$ countInversionsSlow$($array$))$;

$\}$

else $\{$

System.out.println$("$Number of inversions: $"+$ countInversionsFast$($array$))$;

$\}$

$\}$

$\}$