import java.util.*;
import java.util.regex.Pattern;
import java.io.*;

class IO {
	PrintWriter writer;
	BufferedReader reader;
	StringTokenizer tokenizer;
	
	public IO(InputStream in, OutputStream out) {
		reader = new BufferedReader(new InputStreamReader(in));
		writer = new PrintWriter(out);
		tokenizer = new StringTokenizer("");
	}
	
	public String next() {
		try {
			while(tokenizer == null || !tokenizer.hasMoreTokens()) {
				tokenizer = new StringTokenizer(reader.readLine());
			}
			return tokenizer.nextToken();
		}
		catch(IOException exc) {
			exc.printStackTrace();
			return "";
		}
	}
	
	public int nextInt() {
		return Integer.parseInt(next());
	}
	
	public long nextLong() {
		return Long.parseLong(next());
	}
	
	public double nextDouble() {
		return Double.parseDouble(next());
	}
	
	public int[] nextIntArray(int n) {
		int[] arr = new int[n];
		for(int i=0;i<n;++i) {
			arr[i] = nextInt();
		}
		return arr;
	}
	
	public long[] nextLongArray(int n) {
		long[] arr = new long[n];
		for(int i=0;i<n;++i) {
			arr[i] = nextLong();
		}
		return arr;
	}
	
	public double[] nextDoubleArray(int n) {
		double[] arr = new double[n];
		for(int i=0;i<n;++i) {
			arr[i] = nextDouble();
		}
		return arr;
	}
	
	public double[][] nextDoubleArray(int n, int m) {
		double[][] arr = new double[n][];
		for(int i=0;i<n;++i) {
			arr[i] = nextDoubleArray(m);
		}
		return arr;
	}
	
	public long[][] nextLongArray(int n, int m) {
		long arr[][] = new long[n][];
		for(int i=0;i<n;++i) {
			arr[i] = nextLongArray(m);
		}
		return arr;
	}
	
	public int[][] nextIntArray(int n, int m) {
		int arr[][] = new int[n][];
		for(int i=0;i<n;++i) {
			arr[i] = nextIntArray(m);
		}
		return arr;
	}
	
	public void println(String s) {
		writer.println(s);
	}
	
	public void print(String s) {
		writer.print(s);
	}
	
	public void println(long n) {
		writer.println(n);
	}
	
	public void print(long n) {
		writer.print(n);
	}
	
	public void close() {
		writer.flush();
		writer.close();
	}
}

class Question {
	IO io;
	int n, m, arr[], testCases;
	String password;
	String answer;
	
	public Question() {
		io = new IO(System.in, System.out);
		testCases = 1;
	}
	
	public void solveTestCases() {
		while(testCases--!=0) {
			input();
			solve();
			writeAnswer();
		}
		io.close();
	}
	
	public void input() {
		n = io.nextInt();
		password = io.next();
	}
	
	public void writeAnswer() {
		io.println(answer);
	}
	
	public void solve() {
		String digitPattern = "(.*)(\\d+)(.*)";
		String upperPattern = "(.*)([A-Z]+)(.*)";
		String lowerPattern = "(.*)([a-z]+)(.*)";
		String specialCharacters = "!@#$%^&*()-+";
		HashSet<Character> set = new HashSet<Character>();
		for (Character character : specialCharacters.toCharArray()) {
			set.add(character);
		}
		Pattern d = Pattern.compile(digitPattern);
		Pattern u = Pattern.compile(upperPattern);
		Pattern l = Pattern.compile(lowerPattern);
		int length = password.length();
		if(!d.matcher(password).find()) {
			length++;
		}
		if(!u.matcher(password).find()) {
			length++;
		}
		if(!l.matcher(password).find()) {
			length++;
		}
		boolean containsSpecial = false;
		for (Character character : password.toCharArray()) {
			if(set.contains(character)) {
				containsSpecial = true;
			}
		}
		if(!containsSpecial) {
			length++;
		}
		if(length < 6) {
			length = 6;
		}
		answer = Math.abs(password.length() - length) + "";
	}
	
	public static void main(String args[]) {
		Question q = new Question();
		q.solveTestCases();
	}
}