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 s) {
        int count1=0;
        int count2=0;
        int count3=0;
        int count4=0;
        int countf=0;
        for(int i=0;i<n;i++){
            if(s.charAt(i)>='a'&&s.charAt(i)<='z'){
                count1++;
            }
        }
            if(count1>=1){}
            else
                countf++;
        
           for(int i=0;i<n;i++){
            if(s.charAt(i)>='A'&&s.charAt(i)<='Z'){
                count2++;
            }}
            if(count2>=1){}
            else
                countf++;
        
                for(int i=0;i<n;i++){
            if(s.charAt(i)>='0'&&s.charAt(i)<='9'){
                count3++;
            }}
            if(count3>=1){}
            else
                countf++;
        
        
            for(int i=0;i<n;i++){
            if(s.charAt(i)=='!'||s.charAt(i)=='@'||s.charAt(i)=='#'||s.charAt(i)=='$'||s.charAt(i)=='%'||s.charAt(i)=='^'||s.charAt(i)=='&'||s.charAt(i)=='*'||s.charAt(i)=='('||s.charAt(i)==')'||s.charAt(i)=='+'||s.charAt(i)=='-'){
                
                count4++;
            }}
            if(count4>=1){}
            else
                countf++;
        
        if(n+countf>=6)
            return countf;
        else 
            return 6-n;
        
    }

    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();
    }
}