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

import static java.lang.System.in;


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