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 p) {
        
        boolean d = false;
        boolean l = false;
        boolean u = false;
        boolean s = false;
        String sp = "!@#$%^&*()-+";
        
        for(int i=0;i<n;i++) {
           
            char ch = p.charAt(i);
            
            if(ch >= '0' && ch <= '9'){
                d = true;
            }else  if(ch >= 'a' && ch <= 'z'){
                l = true;
            }
            else  if(ch >= 'A' && ch <= 'Z'){
                u = true;
            }
            else if(sp.contains(ch+"")){
                s = true;        
            }
        }
        
        int cnt = 0;
        
        if(!d){
            cnt++;
        }
        
        if(!l){
            cnt++;
        }
        
        if(!u){
            cnt++;
        }
        
        if(!s){
            cnt++;
        }
        
        while(n+cnt<6){
            cnt++;
        }
        return cnt;
    }

    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();
    }
}