using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp3
{
    class Program
    {

        public static int pocetInverzii(string a, string b)
        {
            int[,] dist = new int[a.Length + 1, b.Length + 1];

            for (int i = 0; i < a.Length + 1; i++)
                dist[i, 0] = i;
            for (int i = 0; i < b.Length + 1; i++)
                dist[0, i] = i;
            for(int i = 1; i < a.Length+1; i++)
            {
                for (int j = 1; j < b.Length+1; j++)
                {
                    int t1, t2,t3;
                    t1 = dist[i - 1, j] + 1;
                    t2 = dist[i, j - 1] + 1;
                    t3 = dist[i - 1, j - 1];
                    if (a[i - 1] != b[j - 1])
                    {
                        t3++; 
                    }
                    dist[i, j] = Math.Min(Math.Min(t3, t1), t2);

                }
            }

            for(int i =0; i<a.Length+1;i++)
            {
                
                for(int j =0; j<b.Length+1;j++)
                {

                    Console.Write("{0,3}", dist[i, j]);
                    
                }
                Console.WriteLine();
            }

            return dist[a.Length, b.Length];
        }

        static void Main(string[] args)
        {
            string a = Console.ReadLine();
            string b = Console.ReadLine();

            

            Console.WriteLine(pocetInverzii(a,b));

        }
    }
}