#include <bits/stdc++.h>
int main(void) {
  int pages, papers, tmp1, tmp2;
  tmp1 = scanf("%d", &pages);
  if (tmp1 > 0 && tmp1 < 101)
    ;
  tmp2 = pages % 2;
  papers = pages / 2;
  if (tmp2 == 1) {
    papers += 1;
  }
  return papers;
}
