#include <algorithm>
#include <iostream>
#include <string>
using namespace std;

int score(const string &S, int l, int r) {
  if (l < 0 || r >= S.size()) {
    return 0;
  }

  return score(S, l - 1, r + 1) + (S[l] == S[r] ? 2 : 0);
}

int score(const string &S, int i) {
  return score(S, i - 1, i + 1) + 1;
}

int main() {
  string S;
  cin >> S;

  int len = 0;
  for (int i = 0; i < S.size(); i++) {
    len = max(len, score(S, i));
  }

  for (int i = 0; i < S.size() - 1; i++) {
    len = max(len, score(S, i, i + 1));
  }

  cout << len << endl;

  return 0;
}