#include <cassert>
#include <cmath>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <functional>
#include <iostream>
#include <limits>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;

using Int = long long;

template <class T1, class T2> ostream &operator<<(ostream &os, const pair<T1, T2> &a) { return os << "(" << a.first << ", " << a.second << ")"; };
template <class T> ostream &operator<<(ostream &os, const vector<T> &as) { const int sz = as.size(); os << "["; for (int i = 0; i < sz; ++i) { if (i >= 256) { os << ", ..."; break; } if (i > 0) { os << ", "; } os << as[i]; } return os << "]"; }
template <class T> void pv(T a, T b) { for (T i = a; i != b; ++i) cerr << *i << " "; cerr << endl; }
template <class T> bool chmin(T &t, const T &f) { if (t > f) { t = f; return true; } return false; }
template <class T> bool chmax(T &t, const T &f) { if (t < f) { t = f; return true; } return false; }
#define COLOR(s) ("\x1b[" s "m")


int N;
int scores[2];

void dfs(int l, int r, const string &path) {
  if (l + 1 == r) {
    int mxs[2] = {1, 1};
    for (int i = 0, j = 0; i < (int)path.size(); ++i) {
      for (; j < (int)path.size() && path[i] == path[j]; ++j) {}
      chmax(mxs[path[i] - '0'], j - i + 1);
    }
    scores[0] += mxs[0];
    scores[1] += mxs[1];
  } else {
    const int m = (l + r) / 2;
    dfs(l, m, path + '0');
    dfs(m, r, path + '1');
  }
}

int main() {
#ifdef LOCAL
  for (N = 1; N <= 128; ++N) {
    scores[0] = scores[1] = 0;
    dfs(0, N, "");
    cerr << N << ": " << scores[0] << " " << scores[1] << endl;
    assert(scores[0] <= scores[1]);
  }
#endif
  
  char S[20];
  for (; ~scanf("%s", S); ) {
    N = 0;
    for (char *s = S; *s; ++s) (N <<= 1) |= (*s - '0');
    scores[0] = scores[1] = 0;
    dfs(0, N, "");
    printf("%d\n", scores[1]);
  }
  return 0;
}