#!/usr/bin/perl
use strict;
use warnings;

my ($s, $t) = @ARGV;
print &leven($s, $t) . "\n";

sub min {
  my $min = $_[0];
  foreach my $i (@_) {
    $min = $i if ($i < $min);
  }
  return $min;
}

sub leven {
  my ($s, $t) = @_;
  my ($len_s, $len_t) = (length $s, length $t);
  return $len_s if ($len_t == 0);
  return $len_t if ($len_s == 0);
  my @d;
  for (my $i = 0; $i <= $len_s; ++$i) {
    for (my $j = 0; $j <= $len_t; ++$j) {
      $d[$i][$j] = 0;
      $d[0][$j] = $j;
    }
    $d[$i][0] = $i;
  }
  my @a_s = split //, $s;
  my @a_t = split //, $t;
  for (my $i = 1; $i <= $len_s; ++$i) {
    for (my $j = 1; $j <= $len_t; ++$j) {
      my $subst = ($a_s[$i - 1] eq $a_t[$j - 1]) ? 0 : 1;
      $d[$i][$j] = min($d[$i - 1][$j] + 1, 
		       $d[$i][$j - 1] + 1, 
		       $d[$i - 1][$j - 1] + $subst);
    }
  }
  return $d[$len_s][$len_t];
}