import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.HashSet;
import java.util.Set;

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

		BufferedReader br = null;
		BufferedWriter bw = null;
		int n;
		try {
			br = new BufferedReader(new FileReader("fractii.in"));
			bw = new BufferedWriter(new FileWriter("fractii.out"));

			n = Integer.parseInt(br.readLine());
		} finally {
			if (br != null) {
				br.close();
			}

		}
		Set<Double> set = new HashSet<>();
		if (n == 1) {
			bw.write(1 + "");
			return;
		}
		if (n == 2) {
			bw.write(3 + "");
			return;
		}
		if (n == 3) {
			bw.write(7 + "");
			return;
		}
		int k = 0;
		for (int i = 1; i <= n; i++) {
			k += i - 1;
			for (int j = i + 1; j <= n; j++) {

				set.add(((double) i) / j);
			}
		}
		// System.out.println(set.size() + k);
		bw.write(set.size() + "");

		if (bw != null) {
			bw.close();
		}
	}
}