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 s) {
        // Return the minimum number of characters to make the password strong
        int l=6;
        int d=0,lc=0,uc=0,sc=0;
        for(int i=0;i<n;i++)
        {
            char c=s.charAt(i);
            if(c>='0' && c<='9') {d=1;}
            if(c>='a' && c<='z') {lc=1;}
            if(c>='A' && c<='Z') {uc=1;}
            if(c=='!' || c=='@' || c=='#' || c=='$' || c=='%' || c=='^' || c=='&' || c=='*' || c=='(' || c==')' || c=='-' || c=='+')
            {sc=1;}
        }
        int ans=0;
        if(d==0) ans+=1;
        if(lc==0) ans+=1;
        if(uc==0) ans+=1;
        if(sc==0) ans+=1;
        int temp=ans;
        if(n<6 && temp<(6-n))
        {
           ans=6-temp-n;
            ans+=temp;
            return ans;
        }
        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();
    }
}