#include <bits/stdc++.h>

using namespace std;

int main(void) {
  string s;
  cin >> s;

  int ans = 0, sz = s.size();
  for (int i = 0; i < sz; i++) {
    int sum = 1;
    for (int j = 1; j <= min(i, sz - i - 1); j++) {
      sum += (s[i - j] == s[i + j]) * 2;
    }
    ans = max(ans, sum);
  }
  for (int i = 0; i < sz - 1; i++) {
    if (s[i] != s[i + 1]) continue;
    int sum = 2;
    for (int j = 1; j <= min(i, sz - i - 2); j++) {
      sum += (s[i - j] == s[i + 1 + j]) * 2;
    }
    ans = max(ans, sum);
  }
  cout << ans << endl;

  return 0;
}