//206
#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <math.h>
#include <string>
#include <algorithm>
#include <climits>
#include <vector>
using namespace std;







int levis(string s1, string s2)
{
    int n = s1.length(), m = s2.length();

    if (m == 0)
        return n;
    if (n == 0)
        return m;

    vector<vector<int> > d(n + 1, vector<int>(m + 1));

    for (int i = 0; i <= n; i++)
        d[i][0] = i;
    for (int j = 0; j <= m; j++)
        d[0][j] = j;

    int c = 0, a;

    for (int i = 1; i <= n; i++)
    {
        for (int j = 1; j <= m; j++)
        {
            if (s1[i - 1] == s2[j - 1])
                c = 0;
            else
                c = 1;
            a = min(d[i - 1][j] + 1, d[i][j - 1] + 1);
            d[i][j] = min(a, d[i - 1][j - 1] + c);
        }
    }
    return d[n][m];
}

double gakkar(string s1, string s2)
{
    double c = 0;
    if (s1.length() <= s2.length())
    {
        for (int i = 0; i < s1.length(); i++) {
            if (s1[i] == s2[i])
                c++;
        }
    }
    else
    {
        for (int i = 0; i < s2.length(); i++)
            if (s1[i] == s2[i])
                c++;
    }
    c = c / (s1.length() + s2.length() - c);


    return c;



};

string norm2(string s)
{
    string x, k;
    int i = 0;

    while ((int)s[i] == 32)
        i++;

    for (; i<s.length(); i++)
    {
        if ((int)s[i] == 32)
            if (k.length() > 3)
            {
                x = x + k + " ";
                k = "";
            }
            else
                k = "";
        else
            k = k + s[i];
    }
    if (k.length() > 3)
        x = x + k;
    return x;
}

string norm3(string s)
{
    int i = s.length() - 1;
    while (s[i] == 32)
        i--;
    s = s.substr(0, i);
    return s;
}

string norm1(string s)
{
    string x;
    for (int i = 0; i < s.length(); i++)
    {
        int a = (int)s[i];
        if ((a == 32) || ((a >= 48) && (a <= 57)) || ((a >= 97) && (a <= 122)))
            x = x + s[i];
        if ((a >= 65) && (a <= 90))
        {
            s[i] += 32;
            x = x + s[i];
        }
    }
    return x;
};


int main()
{
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    string s1,s2, m;

    getline(cin, s1);
    getline(cin, s2);

    s1 = norm1(s1);
    s1 = norm2(s1);
    s2 = norm1(s2);
    s2 = norm2(s2);
    //s1 = norm3(s1);
    //s2 = norm3(s2);

    cout.precision(8);

    cout <<  levis(s1, s2);



    return 0;

}