#include<iostream>
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<algorithm>
#include<vector>
#include<math.h>
#include<iomanip>
#include<stack>
#include<queue>
#include<set>
#include<map>

using namespace std;
using ll = long long;
using ull = unsigned long long;
using ld = long double;

//const ll mod = 1000000007;
const ll mod = 998244353;
const ld pi = 3.14159265358979;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  //cout << fixed << setprecision(15);
  string n;
  cin >> n;
  int ans = (n.size() + 1) / 2;
  cout << ans << endl;
  return 0;
}