import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    static int minimumNumber(int y, String p) {
        // Return the minimum number of characters to make the password strong
        int a=0, b=0, c=0, d=0, n=0;
        
        for(int i =0;i<y;i++){
           
            char k = p.charAt(i);
            if(k=='0'||k=='1'||k=='2'||k=='3'||k=='4'||k=='5'||k=='6'||k=='7'||k=='8'||k=='9')
                a++;
            if(k=='!'||k=='@'||k=='#'||k=='$'||k=='%'||k=='^'||k=='&'||k=='*'||k=='('||k==')'||k=='-'||k=='+')
                b++;
            if(Character.isLowerCase(k))
                c++;
            if(Character.isUpperCase(k))
                d++;
            
        }
        if(a==0)
                n++;
            if(b==0)
                n++;
            if(c==0)
                n++;
            if(d==0)
                n++;
        if(y+n<6)
            return n+6-(y+n);
        else
            return n;
    }

    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();
    }
}