import java.util.Scanner;

public class AnagramPeriod {

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

    int totalDel = makeAnagram(a, b);
    System.out.println(totalDel);

  }

  private static int makeAnagram(String strOne, String strTwo) {
    // bacdc
    // dcbac
    // bacdc
    // dcbad

    int[] a_frequency = new int[26]; // 26 numbers of letters in the alphabet.
    int[] b_frequency = new int[26]; // 26 numbers of letters in the alphabet.

    // populate the frequence array for String strOne
    for (char c : strOne.toCharArray()) {
      a_frequency[c - 'a']++;
    }

    // populate the frequence array for String strTwo
    for (char c : strTwo.toCharArray()) {
      b_frequency[c - 'a']++;
    }

    // calculate the total number of deletions needed
    int deletion = 0;
    for (int i = 0; i < 26; i++) {
      deletion += Math.abs(a_frequency[i] - b_frequency[i]);
    }
    return deletion;
  }
}