import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.HashSet;

public class StrongPassword {
	static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	static ArrayList<ArrayList<Integer>> list;
	static HashSet<Integer> hs;
	static ArrayList<Integer> tmp;

	public static void main(String[] args) throws java.lang.Exception {
		int n = Integer.parseInt(br.readLine());
		int d,l,u,sp;
		d=l=u=sp=1;
		String s=br.readLine();
		for(int i=0;i<n;i++){
			char ch=s.charAt(i);
			if(ch>='A' && ch<='Z')
				u=0;
			else if(ch>='a' && ch<='z')
				l=0;
			else if(ch>='0' && ch<='9')
				d=0;
			else
				sp=0;
		}
		int ans=Math.max(6-n,d+l+u+sp);
		System.out.println(ans);
	}
}