#include<iostream>
#include<string.h>
using namespace std;
string a;
string b;
int dp[2002][2002];
int main()
{
	getline(cin,a);
	getline(cin,b);
	int s1=a.length();
	int s2=b.length();
		for(int i=0;i<=s1;i++)
		{
			dp[i][0]=i;
		
		}	
		for(int i=0;i<=s2;i++)
		{
			dp[0][i]=i;
		
		}
	

	
		for(int i=1;i<=s1;i++)
		{
			for(int j=1;j<=s2;j++)
			{
				if(a[i-1]!=b[j-1])
					dp[i][j]=min(dp[i-1][j],min(dp[i][j-1],dp[i-1][j-1]))+1;
				else
					dp[i][j]=min(min(dp[i][j-1],dp[i-1][j-1]),dp[i-1][j-1]-1)+1;				
			} 
			
			
		}	
		cout<<dp[s1][s2];
	
	
}

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        String x=sc.next();
        String y=sc.next();
        int[][] dp=new int[x.length()+1][y.length()+1];
        //初始化
        for (int i = 0; i <= x.length(); i++) {
            dp[i][0]=i;
        }
        for (int j = 0; j <= y.length(); j++) {
            dp[0][j]=j;
        }


        for (int i = 0; i < x.length(); i++) {
            for (int j = 0; j < y.length(); j++) {

                if (x.charAt(i)!=y.charAt(j)){
                    dp[i+1][j+1]=Math.min(  dp[i][j]+1 , Math.min( dp[i][j+1]+1,dp[i+1][j]+1 ) );
                }else{
                    dp[i+1][j+1]=dp[i][j];
                }
            }
        }
        System.out.println(dp[x.length()][y.length()]);

    }
}