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 no=0,s=0,u=0,l=0,rc=0;
        for(int i=0;i<n;i++)
        {   if(Character.isDigit(password.charAt(i)))
            no++;
            if(Character.isUpperCase(password.charAt(i)))
            u++;
            if(Character.isLowerCase(password.charAt(i)))
            l++;
            if(password.charAt(i)=='!'||password.charAt(i)=='@'||password.charAt(i)=='#'||password.charAt(i)=='$'||password.charAt(i)=='%'||password.charAt(i)=='*'||password.charAt(i)=='^'||password.charAt(i)=='&'||password.charAt(i)=='('||password.charAt(i)==')'||password.charAt(i)=='-'||password.charAt(i)=='+')
            s++;
               }
        
        if(no==0)
        rc++;
        if(u==0)
        rc++;
        if(l==0)
        rc++;
        if(s==0)
        rc++;
        if(n+rc<6)
        rc+=6-(n+rc);
        return rc;
               }
      

    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();
    }
}