#include <bits/stdc++.h>
using namespace std;
struct _ {
  _() { ios_base::sync_with_stdio(0); }
} _;
template <class A, class B>
ostream &operator<<(ostream &o, pair<A, B> t) {
  o << "(" << t.first << ", " << t.second << ")";
  return o;
}
template <class T>
string tostring(T first, int len = 0, char c = '0') {
  stringstream ss;
  ss << first;
  string r = ss.str();
  if (r.length() < len) r = string(len - r.length(), c) + r;
  return r;
}
template <class T>
void PV(T a, T b, int n = 0, int w = 0, string s = " ") {
  int c = 0;
  while (a != b) {
    cout << tostring(*a++, w, ' ');
    if (a != b && (n == 0 || ++c % n))
      cout << s;
    else
      cout << endl;
  }
}
template <class T>
inline bool chmin(T &a, T b) {
  return a > b ? a = b, 1 : 0;
}
template <class T>
inline bool chmax(T &a, T b) {
  return a < b ? a = b, 1 : 0;
}
const long long linf = 0x3f3f3f3f3f3f3f3fLL;
const int inf = 0x3f3f3f3f;
const int mod = int(1e9) + 7;
const int N = 1111111;
string s;
int n;
vector<int> d;
int dp[N];
int main() {
  cin >> s;
  n = s.length();
  int cnt = 0;
  for (int i = n - 1; i >= 0 && s[i] == s[0]; i--) cnt++;
  s = s.substr(n - cnt) + s.substr(0, n - cnt);
  vector<int> v;
  for (int i = 0; i < s.length();) {
    int j = i;
    while (j < s.length() && s[j] == s[i]) j++;
    v.push_back(min(3, j - i));
    i = j;
  }
  for (int i = 0; i < v.size(); i++) {
    int first = v[i];
    while (first--) d.push_back(i % 2);
  }
  n = d.size();
  int res = 0;
  for (int used = 0; used < 2; used++) {
    memset(dp, 0, sizeof(dp));
    ;
    dp[0] = used;
    for (int i = 1; i < n; i++) {
      dp[i] = 1;
      for (int j = i - 1; j >= 0; j--) {
        if (d[j] != d[i - 1]) {
          for (int k = j; k >= j - 10 && k >= 0; k--) chmax(dp[i], dp[k] + 1);
          break;
        }
      }
    }
    int last = n - 1;
    if (used)
      while (last >= 0 && d[last] == d[n - 1]) last--;
    if (last == -1)
      res = 1;
    else {
      chmax(res, *max_element(dp, dp + last + 1));
    }
  }
  cout << res << endl;
  return 0;
}
