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) {
        char ar[]  = password.toCharArray();
        int k=4;
        String rs = "!@#$%^&*()-+";
        for(int i=0;i<n;i++)
        if(ar[i]>=48 && ar[i]<=57)
        {
            k--;
            break;
        }
        
        for(int i=0;i<n;i++)
        if(ar[i]>=97 && ar[i]<=122)
        {
            k--;
            break;
        }
        for(int i=0;i<n;i++)
        if(ar[i]>=65 && ar[i]<=91)
        {
            k--;
            break;
        }
        for(int i=0;i<n;i++)
        if(rs.contains(ar[i]+""))
        {
            k--;
            break;
        }
        
        return Math.max(6,n+k);
    }

    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-n);
        in.close();
    }
}