#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int counter = 0;
  while (n != 0) {
    counter++;
    n = n - 2;
  }
  cout << (n % 2 == 1 ? (counter + 1) : counter) << "\n";
  return 0;
}
