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


public class Tester2 {

	public static void main(String[] args) throws IOException{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		int y = Integer.parseInt(br.readLine());
		if(1970<=y && y<=2017)
			System.out.println(2017-y);
	}
}