import java.util.Scanner;
public class summationofseries {
    public static void main (String[] args ){
        Scanner scanner= new Scanner(System.in);
        int k = scanner.nextInt();
        double S =0;
        int a;
        for(  a = 1;S<k;a++){
            S += 1.0/a;
        }
     System.out.println(a);
    }
}