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 b=0,c=p.length();
            boolean w,x,y,z;
            x=y=z=w=false;
            for(int i=65;i<=90;i++){
                if(p.indexOf((char)i)!=-1)
                    x=true;
                if(p.indexOf((char)(i+32))!=-1)
                    y=true;
            }
        String num = "0123456789";
        for(int i=0;i<num.length();i++){
            if(p.indexOf(num.charAt(i))!=-1){
                w=true;
                break;
            }
        }
        String sp = "!@#$%^&*()-+";
        for(int i=0;i<sp.length();i++){
            if(p.indexOf(sp.charAt(i))!=-1){
                z=true;
                break;
            }
        }
        if(x==false)
            b++;
        if(y==false)
            b++;
        if(z==false)
            b++;
        if(w==false)
            b++;
        if(p.length()<6)
        {
            if((c+b)>=6)
                return b;
            else
                return(b+6-(b+c));
        }else
            return b;
        
            
    }

    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();
    }
}