import java.util.Scanner;

public class Solution {
  private static final String special_characters = "!@#$%^&*()-+";
  private static final int MIN_LENGTH = 6;

  static int minimumNumber(int n, String password) {
    // Return the minimum number of characters to make the password strong
    int symbolsToAdd = 0;
    boolean hasNumber =false;
    boolean hasLowerCase = false;
    boolean hasUpperCase = false;
    boolean hasSpecial = false;
    for (int i = 0; i < password.length(); i++) {
      if (Character.isDigit(password.charAt(i))) {
        if (!hasNumber) {
          hasNumber = true;
        }
        continue;
      }
      if (Character.isLetter(password.charAt(i))) {
        if (!hasLowerCase && Character.isLowerCase(password.charAt(i))) {
          hasLowerCase = true;
        }
        if (!hasUpperCase && Character.isUpperCase(password.charAt(i))) {
          hasUpperCase = true;
        }
        continue;
      }
      if (special_characters.indexOf(password.charAt(i)) != -1) {
        hasSpecial = true;
      }
    }
    if (!hasNumber) {
      symbolsToAdd++;
    }
    if (!hasLowerCase) {
      symbolsToAdd++;
    }
    if (!hasUpperCase) {
      symbolsToAdd++;
    }
    if (!hasSpecial) {
      symbolsToAdd++;
    }
    if (password.length() + symbolsToAdd < MIN_LENGTH) {
      symbolsToAdd = MIN_LENGTH - password.length();
    }
    return symbolsToAdd;
  }


    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        String password = in.next();
        int answer = minimumNumber(n, password);
        System.out.println(answer);
        in.close();
    }
}