import java.io.*;
import java.util.*;
import java.math.*;

class Main244 {
	
	public static void main (String[] args) throws IOException {
		BufferedReader br = 
			new BufferedReader(new InputStreamReader(System.in));
		
		int n = Integer.parseInt(br.readLine());
		System.out.println(n - 1);
		
	}
}