import java.util.Scanner;

public class EditDistance {

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

        String s = scan.next();
        String t = scan.next();

        System.out.println(editDistance(s, t));
      }

    public static int editDistance(String A, String B) {
        int m = B.length();
        int n = A.length();
        int[][] D = new int[n + 1][m + 1];

        for (int i = 0; i < n + 1; i++) {
            D[i][0] = i;
        }
        for (int j = 0; j < m + 1; j++) {
            D[0][j] = j;
        }

        for (int j = 1; j < m + 1; j++) {
            for (int i = 1; i < n + 1; i++) {
                int insertion = D[i][j - 1] + 1;
                int deletion = D[i - 1][j] + 1;
                int match = D[i - 1][j - 1];
                int mismatch = D[i - 1][j - 1] + 1;
                if (A.toCharArray()[i - 1] == B.toCharArray()[j - 1]) {
                    D[i][j] = Math.min(insertion, Math.min(deletion, match));
                } else {
                    D[i][j] = Math.min(insertion, Math.min(deletion, mismatch));
                }
            }
        }

        return D[n][m];
    }

}