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

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