#! perl -slw
use strict;
use Time::HiRes qw[ time ];

our $B //= 64;
$/ = \( $B *1024 );

binmode STDIN, ':raw:perlio';

my $start = time;
my $count = 0;
while( <STDIN> ) {
   ++$count while m[123]g;
}
printf "Found %d matches in %.3f seconds using %d kb reads\n",
    $count, time()-$start, $B;