#include <iostream>
#include <fstream>
#include <cstring>
using namespace std;
ifstream fin("siruri2.in");
ofstream fout("siruri2.out");

char s1[501], s2[501];
int n, m;
///matrice costuri
int a[501][501];

int main()
{
    int i, j;
    fin.getline(s1,501);
    fin.getline(s2,501);

    n = strlen(s1);
    m = strlen(s2);

    for(i=1; i<=n; i++)
    {
        a[i][0] = i;
        //transform literele mari in litere mici
        if(s1[i-1] >= 'A' && s1[i-1] <= 'Z')
            s1[i-1] = s1[i-1] + 32;
    }
    for(i=1; i<=m; i++)
    {
        a[0][i] = i;
        //transform literele mari in litere mici
        if(s2[i-1] >= 'A' && s2[i-1] <= 'Z')
            s2[i-1] = s2[i-1] + 32;
    }

    for(i=1; i<=n; i++)
        for(j=1 ; j<=m; j++)
            if(s1[i-1]==s2[j-1])
                a[i][j]=a[i-1][j-1]; ///SALT
            else if(a[i-1][j-1] <= a[i-1][j] && a[i-1][j-1]<= a[i][j-1])
                   a[i][j] = 1 + a[i-1][j-1]; ///MODIFICARE
            else if(a[i][j-1]<=a[i-1][j-1] && a[i][j-1] <= a[i-1][j])
                   a[i][j] = 1 + a[i][j-1]; ///ADAUGARE
            else
                 a[i][j] = 1 + a[i-1][j]; ///STERGERE

    fout << a[n][m];
    return 0;
}