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) {
     int a2=0,a3=0,a4=0,a5=0,ans=0;
        String str= password;
     
        for(int i=0;i<n;i++)
        {
            if(str.charAt(i)>='0' && str.charAt(i)<='9')
            {
                a2++;
            }
            else
            if(str.charAt(i)>='a' && str.charAt(i)<='z')
            {
                a3++;
            }
            
            else
            if(str.charAt(i)>='A' && str.charAt(i)<='Z')
            {
                a4++;
            }
           else 
               if(str.charAt(i)=='!' || str.charAt(i)=='@' || str.charAt(i)=='#' )
               {
                   a5++;
               }
            else
                if( str.charAt(i)=='$' || str.charAt(i)=='^' || str.charAt(i)=='&' || str.charAt(i)=='*' ||str.charAt(i)=='%'  )
                    a5++;
            else
                if(  str.charAt(i)=='(' || str.charAt(i)==')' || str.charAt(i)=='-' || str.charAt(i)=='+')
                    a5++;
        }
          
            if(a2==0)
                ans+=1;
            if(a3==0)
                ans+=1;
            if(a4==0)
                ans+=1;
         if(a5==0)
                ans+=1;
            if(ans+password.length()<6)
                return 6-(password.length());
           
                return ans;
        
    }

    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();
    }
}