// Leetcode 72题 编辑距离

package kuaishou;

import java.util.Scanner;

//public class Main {
public class LevenshteinDistance {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        while (in.hasNext()) {
            String a = in.nextLine();
            String b = in.nextLine();

            if(a == null || a.length() == 0){
                if(b == null || b.length() == 0)
                    System.out.println(0);
                else
                    System.out.println(b.length());
            }
            else if(b == null || b.length() == 0){
                System.out.println(a.length());
            }else{
                int [][] distance = new int [a.length()+1][b.length()+1];

                for(int i=0; i<=a.length(); i++)
                    distance[i][0] = i;

                for(int i=0; i<=b.length(); i++)
                    distance[0][i] = i;

                for(int i=1; i<=a.length(); i++){
                    for(int j=1; j<=b.length(); j++){
                        int min1, min2;

                        if(a.charAt(i-1) == b.charAt(j-1))
                            min1 = distance[i-1][j-1];
                        else
                            min1 = distance[i-1][j-1] + 1;

                        min2 = Math.min(distance[i][j-1]+1, distance[i-1][j]+1);

                        distance[i][j] = Math.min(min1, min2);

                    }
                }

                System.out.println(distance[a.length()][b.length()]);
            }

        }
    }
}