#!/usr/bin/perl

use strict;
use warnings;
my @s = split //, $ARGV[0];
my @t = split //, $ARGV[1];
my ($m, $n) = ($#s + 1, $#t + 1);
my @d;

sub min {
  my ($a, $b, $c) = @_;
  return ($a < $b ? ($a < $c ? $a : $c) : ($b < $c ? $b : $c));
}

sub edit {
  my ($i, $j) = @_;
  if ($d[$i][$j] != -1) {
  	return $d[$i][$j];
  }
  if ($s[$i - 1] eq $t[$j - 1]) {
   	$d[$i][$j] = edit($i - 1, $j - 1);
  } else {
    	$d[$i][$j] = 1 + min(edit($i - 1, $j - 1), 
		  	   edit($i - 1, $j), 
		    	 edit($i, $j - 1));
  }
  return $d[$i][$j];
}
for (my $i = 0; $i <= $m; ++$i) {
  for (my $j = 0; $j <= $n; ++$j) {
    	$d[$i][$j] = -1;
  }
}
for (my $i = 0; $i <= $m; ++$i) {
  $d[$i][0] = $i;
}
for (my $j = 0; $j <= $n; ++$j) {
  $d[0][$j] = $j;
}
print &edit($m, $n), "\n";