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 c=0;
            int dig=0;int lc=0;int spcc=0;int uc=0;
            char spc[]={'!','@','#','$','%','^','&','*','(',')','-','+'};
            for(int i=0;i<password.length();i++){
                char ch=password.charAt(i);
                if(dig==0)
                    if(Character.isDigit(ch)){
                        dig=1;
                    }
                if(lc==0)
                    if(Character.isLowerCase(ch)){
                        lc=1;
                    }
                if(uc==0)
                    if(Character.isUpperCase(ch)){
                        uc=1;
                    } 
                if(spcc==0)
                    for(int j=0;j<spc.length;j++){
                        if(spc[j]==ch){
                            spcc=1;
                        }
                    }
            }
        if(dig==0)
            c++;

        if(lc==0)
            c++;

        if(uc==0)
            c++;

        if(spcc==0)
            c++;

        if((c+n)>=6)
            return c;
        else
            return (6-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();
    }
}