#include <bits/stdc++.h>
using namespace std;
template <class T>
using vv = vector<vector<T>>;
template <class T>
ostream &operator<<(ostream &os, const vector<T> &t) {
  os << "{";
  for (int(i) = 0; (i) < (t.size()); ++(i)) {
    os << t[i] << ",";
  }
  os << "}" << endl;
  return os;
}
template <class T, size_t n>
ostream &operator<<(ostream &os, const array<T, n> &t) {
  os << "{";
  for (int(i) = 0; (i) < (n); ++(i)) {
    os << t[i] << ",";
  }
  os << "}" << endl;
  return os;
}
template <class S, class T>
ostream &operator<<(ostream &os, const pair<S, T> &t) {
  return os << "(" << t.first << "," << t.second << ")";
}
template <class S, class T, class U>
ostream &operator<<(ostream &os, const tuple<S, T, U> &t) {
  return os << "(" << get<0>(t) << "," << get<1>(t) << "," << get<2>(t) << ")";
}
template <class S, class T, class U, class V>
ostream &operator<<(ostream &os, const tuple<S, T, U, V> &t) {
  return os << "(" << get<0>(t) << "," << get<1>(t) << "," << get<2>(t) << ","
            << get<3>(t) << ")";
}
template <class S, class T, class U, class V, class W>
ostream &operator<<(ostream &os, const tuple<S, T, U, V, W> &t) {
  return os << "(" << get<0>(t) << "," << get<1>(t) << "," << get<2>(t) << ","
            << get<3>(t) << "," << get<4>(t) << ")";
}
template <class T>
inline bool MX(T &l, const T &r) {
  return l < r ? l = r, 1 : 0;
}
template <class T>
inline bool MN(T &l, const T &r) {
  return l > r ? l = r, 1 : 0;
}
const long long MOD = 1e9 + 7;
int main() {
  ios_base::sync_with_stdio(false);
  cout << fixed << setprecision(0);
  string s;
  cin >> s;
  s += s;
  int n = s.size();
  int re = 0;
  for (int(i) = 0; (i) < (2); ++(i)) {
    int c = 0;
    for (int(j) = 0; (j) < (n); ++(j)) {
      if ((s[j] == 'b') == ((j + i) % 2))
        ++c;
      else
        c = 0;
      MX(re, c);
    }
  }
  cout << min(re, n / 2) << endl;
  return 0;
}
