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[] arr = new int[4];
        int ans = 0;
        String[] str = { "0123456789","abcdefghijklmnopqrstuvwxyz", "ABCDEFGHIJKLMNOPQRSTUVWXYZ", "!@#$%^&*()-+"};
        arr[0] = 0;
        arr[1] = 0;
        arr[2] = 0;
        arr[3] = 0;
        for(int i =0;i<n;i++)
        {
            for(int j =0;j<4;j++){
            if(str[j].contains(password.charAt(i)+"")) {
                arr[j] =1;
                break;
            }
        }
        }
        for(int i =0;i<4;i++)
        {
            if(arr[i] == 0) ans+=1;
        }
        if(n+ans<6) return 6-n;
        else 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();
    }
}