#include <bits/stdc++.h>
using namespace std;
int main() {
  long long a;
  cin >> a;
  if (a == 0)
    cout << "0" << endl;
  else if (a % 2 == 0)
    cout << (a / 2) << endl;
  else
    cout << (a / 2) + 1 << endl;
  return 0;
}
