IRON scripter Powershell challenge

ironscripter_pscryptogram

$crypto = @"
P k T r 2 s z 2 * c F -
r a z 7 G u D 4 w 6 U #
g c t K 3 E @ B t 1 a Y
Q P i c % 7 0 5 Z v A e
W 6 j e P R f p m I ) H
y ^ L o o w C n b J d O
S i 9 M b e r # ) i e U
* f 2 Z 6 M S h 7 V u D
5 a ( h s v 8 e l 1 o W
Z O 7 l p K y J l D z $
- j I @ t T 2 3 R a i k
q = F & w B 6 c % H l y
"@
$test=(($crypto.replace(' ','')).replace("`r`n","")).ToCharArray()

$a=0
for($x=1;$x -lt $test.Length;$x++)
{
for($y=1;$y -lt $test.Length;$y++ )
{
"$x is $x"
"$y is $y"
[char[]]$output=''
while($a -le $test.Length)

{
    
    $a+=$x
    #$a
    $output +=$test[$a-1] 
    $a+=$y
    $output+=$test[$a-1]
    
}
$output -join ''
$a=0
}
}