import java.util.*;
import java.io.*;
//acbd
//badce

public class Main
{

    static final int N = 1010;
    static int ans;

    static int[][] f = new int[N][N];
    static char[] a = new char[N], b = new char[N];

    public static void main(String args[]) throws IOException
    {
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        PrintWriter log = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));

        int n = Integer.parseInt(in.readLine());
        String A = in.readLine();
        for(int i = 1; i <= n; i++) a[i] = A.charAt(i - 1);
        int m = Integer.parseInt(in.readLine());
        String B = in.readLine();
        for(int i = 1; i <= m; i++) b[i] = B.charAt(i - 1);

        int ca = n, cb = m;

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

        for(int i = 1; i <= n; i++)
        {
            for(int j = 1; j <= m; j++)
            {
                f[i][j] = Math.min(f[i-1][j] + 1,f[i][j-1] + 1);
                f[i][j] = Math.min(f[i][j],f[i - 1][j -1] + (a[i] == b[j] ? 0 : 1));
            }
        }

        log.println(f[n][m]);
        log.flush();
    }
}