package yukicoder;

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

public class Main {
	public static void main(String[] args) {
		BufferedReader read = new BufferedReader(new InputStreamReader(System.in));

		try {
			System.out.println(Integer.parseInt(read.readLine()) - 1);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

}