import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {
	
    static int minimumNumber(int n, String password) {
   	 int count=0;
   	 
   	 boolean hasDigit=check(password, new Check() {
   		 @Override
   		public boolean isAcceptable(char c)
   		{
   			return Character.isDigit(c);
   		}
   	 });
   	 
   	 boolean hasLowerCase=check(password, new Check() {
   		 @Override
   		public boolean isAcceptable(char c)
   		{
   			return Character.isLowerCase(c);
   		}
   	 });
   	 
   	 boolean hasUpperCase=check(password, new Check() {
   		 @Override
   		public boolean isAcceptable(char c)
   		{
   			return Character.isUpperCase(c);
   		}
   	 }); 
   	 
   	 boolean hasSpecial=check(password, new Check() {
   		 @Override
   		public boolean isAcceptable(char c)
   		{
   			return "!@#$%^&*()-+".indexOf(c)>=0;
   		}
   	 });
   	 
   	 if(!hasDigit)
   		 count++;
   	 if(!hasLowerCase)
   		 count++;
   	 if(!hasUpperCase)
   		 count++;
   	 if(!hasSpecial)
   		 count++;
   	 
   	 count+=Math.max((6-(password.length()+count)), 0);
   	 return count;
    }
    
    private static boolean check(String s, Check check)
    {
   	 for(int i=0; i<s.length(); i++)
   	 {
   		 if(check.isAcceptable(s.charAt(i)))
   			 return true;
   	 }
   	 
   	 return false;
    }    

    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();
    }
        
    interface Check
    {
   	 public boolean isAcceptable(char c);
    }
}