#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define rep(i, n) for (int i = 0; i < (n); i++)
#define P pair<int, int>

int main() {
  string s;
  cin >> s;
  int n = (int)s.size();
  cout << (n+1)/2 << endl;


}