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 lc=1,uc=1,sc=1,dig=1,len=6;
        for(int i=0;i<password.length();i++){
            char c= password.charAt(i);
            if(len>0)
                len--;
            
            if(dig>0 && Character.isDigit(c))
                dig--;
            
            if(lc>0 && Character.isLowerCase(c))
                lc--;
            
            if(uc>0 && Character.isUpperCase(c))
                uc--;
            
            if(sc>0 && (c=='!' || c=='@' || c=='#' || c=='$' || c=='%' ||c=='^' || c=='&'
               || c=='*' || c=='(' || c==')' || c=='-' || c=='+'))
                sc--;
            
        }
        
        int count = dig+sc+lc+uc;
        //System.out.println("len:"+len+" count:"+count);
        
        return Math.max(len,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();
    }
}