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) {
        String sl="!@#$%^&*()-+";
        boolean sm=false,lr=false,num=false,spl=false;
        int c=0;
        for(int i=0;i<n;i++)
        {
            char a=password.charAt(i);
            if(a>='a' && a<='z' && !sm)
                sm=true;
            else if(a>='A' && a<='Z' && !lr)
                lr=true;
            else if(a>='0' && a<='9' && !num)
                num=true;
            else if(sl.indexOf(a)>=0 && !spl)
                spl=true;
        }
        //System.out.print(sm+" "+lr+" "+num+" "+spl);
        if(!sm)
            c++;
        if(!lr)
            c++;
        if(!num)
            c++;
        if(!spl)
            c++;
        n+=c;
        if(n<6)
            c+=6-n;
        return c;    
        // Return the minimum number of characters to make the password strong
    }

    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();
    }
}