/* -*- coding: utf-8 -*-
 *
 * 1986.cc:  No.1986 Yummy - yukicoder
 */

#include<cstdio>
#include<algorithm>
 
using namespace std;

/* constant */

/* typedef */

/* global variables */

/* subroutines */

/* main */

int main() {
  int n;
  scanf("%d", &n);

  printf("%d\n", (n & 1) ? 1 : n / 2);
  return 0;
}