Finding a Space in a 3D Random Walk Perl

#!/usr/bin/perl
#
# Finding a space in random 3D walk
#

# Size of Grid
$x = 2500;
$y = 2500;
$z = 2500;



# Position of Space to find
$a = int(rand(5000));
$b = int(rand(5000-$a));
$c = int(rand(5000 - $a + $b));

$step = 0;
while(1)
{

 $minus = int(rand(10));
 if($minus >=5) {$xr = int(rand(100)); $x = $x - $xr;}
 else { $xr = int(rand(100)); $x = $x + $xr; }
 if($x > 10000){ $x = 9999;}
 if($x < 0){ $x = 0;}
 $minus1 = int(rand(10));
 if($minus1 >=5) {$yr = int(rand(100-$xr)); $y = $y - $yr;}
 else { $yr = int(rand(100-$xr)); $y = $y + $yr; }
 if($y > 10000){ $y = 9999;}
 if($y < 0){ $y = 0;}

 $minus2 = int(rand(10));
 if($minus2 >=5) {$zr = (100 - ($xr + $yr)); $z = $z - $zr;}
 else { $zr = (100 - ($xr + $yr)); $z = $z + $zr; }
 if($z > 10000){ $z = 9999;}
 if($z < 0){ $z = 0;}

 print "$a : $b : $c | $minus $x $xr : $minus1 $y $yr : $minus2 $z $zr\n\n";

# How big is the space we want to find and Did we find it?
if($x <= ($a+5) && $x >= ($a-5) && $y <= ($b+5) && $y >= ($b-5) && $z <= ($c+5) && $z >= ($c-5)){ print "WINNER: $steps\n\n"; die; }




$step++;
}