#!/usr/bin/perl -l
$N=pop;print 1/$N*grep{%h=map{int
rand(10),1}1..$ARGV[0];10==keys%h}1..$N
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#! /usr/bin/perl
use strict;
# $stats[$i][$j] will be the number of ways to have used $j different
# digits in a $i digit number.
my @stats = [1, map 0, 1..10];
my $i = 0;
while ($stats[$i][10]*2 < 10**$i) {
  my $last_stats = $stats[$i];
  $i++;
  my $next_stats = $stats[$i] = [map 0, 0..10];
  for my $j (0..10) {
    $next_stats->[$j] += $j*$last_stats->[$j];
    $next_stats->[$j+1] += (10 - $j)*$last_stats->[$j];
  }
}
print $i, "\n";
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