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 p) {
       int count=0;
        
        
        
        int sl=0,cl=0,d=0,sc=0;
        for(int i=0;i<n;i++)
        {
            char ch=p.charAt(i);
            
            if(ch>='a' && ch<='z')sl++;
            else
            if(ch>='A' && ch<='Z')cl++;
            else
            if(ch>='0'&&ch<='9')d++;
            else
                sc++;
        }
        
        
        if(sl==0)count++;
        
        if(cl == 0)count++;
        
        if(d==0)count++;
        
        if(sc==0)count++;
        
        n = n + count;
        
        if(n<6)
            count = count + (6 - n) ;
        
        return count;
        
        
        
        
    }

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