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