import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class No0244 {
	public static void main(String[] args) {
		int num = 0;
		
		try (BufferedReader br = 
new BufferedReader(new InputStreamReader(System.in))) {
			num = Integer.parseInt(br.readLine()) - 1;
		} catch (NumberFormatException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
		System.out.println(num);
	}
}