import java.util.Scanner;

public class yukicoder_175 {
	public static void main(String[] args) {
		Scanner stdIn = new Scanner(System.in);
		
		int l = stdIn.nextInt();
		int n = stdIn.nextInt();
		
		String[] dna = new String[n];
		
		int tori = 0;
		
		for (int i = 0; i < n; i++) {
			dna[i] = stdIn.next();
			tori += Math.pow(2, l - dna[i].length());
		}
		
		System.out.println(tori);
	}
}