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

public class Password {

    static int minimumNumber(int n, String password) {
        HashSet<Character> numbers = new HashSet<>();        
        for(char c : "0123456789".toCharArray())
        	numbers.add(c);
        
        HashSet<Character> lowerCase = new HashSet<>();        
        for(char c : "abcdefghijklmnopqrstuvwxyz".toCharArray())
        	lowerCase.add(c);

        HashSet<Character> upperCase = new HashSet<>(); 
        for(char c : "ABCDEFGHIJKLMNOPQRSTUVWXYZ".toCharArray())
        	upperCase.add(c);
        
        HashSet<Character> spl = new HashSet<>();       
        for(char c : "!@#$%^&*()-+".toCharArray())
        	spl.add(c);
        
        int len = password.length();
        
        boolean hasDigit=false,hasLowerCase=false,hasUpperCase=false,hasSpecial=false;
        
        for(int i=0;i<len;i++){
            char chk = password.charAt(i);
            if(!hasDigit && numbers.contains(chk))
            	hasDigit=true;
            if(!hasLowerCase && lowerCase.contains(chk))
            	hasLowerCase=true;
            if(!hasUpperCase && upperCase.contains(chk))
            	hasUpperCase=true;
            if(!hasSpecial && spl.contains(chk))
            	hasSpecial=true;
            if(hasDigit&&hasLowerCase&&hasUpperCase&&hasSpecial&&len>=6)
            	break;
        }
        int count=0;
        if(!hasDigit)
        	count++;
        if(!hasLowerCase)
        	count++;
        if(!hasUpperCase)
        	count++;
        if(!hasSpecial)
        	count++;
        if(len+count<6)
        	count += 6-(len+count);
        return count;
    }

    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();
    }
}