#include <bits/stdc++.h>
using namespace std;
const int MOD = 1000000007;
template <class T>
typename T::value_type arr_sum(const T& v, int n) {
  typename T::value_type sum = 0;
  for (int i = (0); i < (n); ++i) sum += v[i];
  return sum;
}
struct Sync_stdio {
  Sync_stdio() {
    cin.tie(NULL);
    ios_base::sync_with_stdio(false);
  }
} _sync_stdio;
int solve(vector<int> v) {
  reverse(v.begin(), v.end());
  int res = 0;
  for (int i = (0); i < (int(v.size()) - 1); ++i) {
    if (v[i] == 0) {
      continue;
    }
    ++res;
    --v[i + 1];
  }
  return res;
}
int main() {
  string s;
  cin >> s;
  int n = s.size();
  vector<int> v;
  for (int i = (0); i < (n); ++i) {
    if (i == 0 || s[i] != s[i - 1]) {
      v.push_back(1);
    } else {
      ++v[int(v.size()) - 1];
    }
  }
  if (s[0] == s.back()) {
    v[0] += v[int(v.size()) - 1];
    v.pop_back();
  }
  for (int i = (0); i < (v.size()); ++i) {
    v[i] = min(v[i], 2);
  }
  if (count(v.begin(), v.end(), 2) == v.size()) {
    cout << v.size();
    return 0;
  }
  int x = 0;
  while (v.back() == 2) {
    ++x;
    v.pop_back();
  }
  vector<int> y = vector<int>(x, 2);
  v.insert(v.begin(), y.begin(), y.end());
  int res = solve(v);
  v.pop_back();
  v.insert(v.begin(), 1);
  reverse(v.begin(), v.end());
  res = max(res, solve(v));
  cout << res;
}
