import java.util.*;
public class Main {
  public static void main (String[] atgs){
    Scanner sc =new Scanner(System.in);
    int a = sc.nextInt();
    int b = (a+1)%2;
    System.out.println( (a+1-b)/2 );
  }
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz