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 up=0,lo=0,di=0,sp=0,min=0,ct=0;
        char[] ch=password.toCharArray();
        for(int i=0;i<n;i++)
        {
            char c=ch[i];
            if(Character.isUpperCase(c)){
                up++;
            }
            if(Character.isLowerCase(c)){
                lo++;
            }
            if(Character.isDigit(c)){
                di++;
            }
            if(c=='!'||c=='@'||c=='#'||c=='$'||c=='%'||c=='^'||c=='&'||c=='*'||c=='('||c==')'||c=='-'||c=='+'){
                sp++;
            }
        }
        if(up==0)
        {
            min++;
        }
        if(lo==0)
        {
            min++;
        }
        if(di==0)
        {
            min++;
        }
        if(sp==0)
        {
            min++;
        }
        if(n+min<6)
        {
           ct=6-(n+min);
        }
        return (min+ct);
    }
    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();
    }
}