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) {
        // Return the minimum number of characters to make the password strong
        int count=0;
        char a[]=password.toCharArray();
        if(n<=6)
        {
            int flag=0;
            for(int i=0;i<n;i++)
            {
                if(Character.isDigit(a[i]))
                {
                    flag=1;
                    break;
                }        
            }
            if(flag==0)
                count++;
            flag=0;
            for(int i=0;i<n;i++)
            {
                if(Character.isLowerCase(a[i]))
                {
                    flag=1;
                    break;
                }
            }
            if(flag==0)
                count++;
            flag=0;
            for(int i=0;i<n;i++)
            {
                if(Character.isUpperCase(a[i]))
                {
                    flag=1;
                    break;
                }
            }
            if(flag==0)
                count++;
            flag=0;
            String x="!@#$%^&*()-+";
            char b[]=x.toCharArray();
            for(int i=0;i<n;i++)
                for(int j=0;j<b.length;j++)
                    if(a[i]==b[j])
                    {
                        flag=1;
                        break;
                    }
            if(flag==0)
                count++;
            if(count+n>=6)
                return count;
            else
                return 6-n;
        }
        else
        {
            int flag=0;
            for(int i=0;i<n;i++)
            {
                if(Character.isDigit(a[i]))
                {
                    flag=1;
                    break;
                }
            }
            if(flag==0)
                count++;
            flag=0;
            for(int i=0;i<n;i++)
            {
                if(Character.isLowerCase(a[i]))
                {
                    flag=1;
                    break;
                }
            }
            if(flag==0)
                count++;
            flag=0;
            for(int i=0;i<n;i++)
            {
                if(Character.isUpperCase(a[i]))
                {
                    flag=1;
                    break;
                }
            }
            if(flag==0)
                count++;
            flag=0;
            String x="!@#$%^&*()-+";
            char b[]=x.toCharArray();
            for(int i=0;i<n;i++)
                for(int j=0;j<b.length;j++)
                    if(a[i]==b[j])
                    {
                        flag=1;
                        break;
                    }
            if(flag==0)
                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();
    }
}