import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.HashSet;
import java.util.Set;

public class Fractii {
	public static void main(String[] args) throws IOException {

		FileInputStream in = null;
		FileOutputStream out = null;
		int n;
		try {
			in = new FileInputStream("fractii.in");
			out = new FileOutputStream("fractii.out");

			n = in.read();
		} finally {
			if (in != null) {
				in.close();
			}
			if (out != null) {
				out.close();
			}

		}
		Set<Double> set = new HashSet<>();

		for (int i = 1; i <= n; i++) {
			for (int j = 1; j <= n; j++) {
				set.add(((double) i) / j);
			}
		}
		out.write(set.size());
	}
}