/* -*- coding: utf-8 -*-
 *
 * 273.cc: No.273 回文分解 - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

/* typedef */

/* global variables */

/* subroutines */

/* main */

int main() {
  string s;
  cin >> s;
  int n = s.size();

  int maxl = 1;

  for (int i = 0; i < n; i++) {
    for (int j = i - 1, k = i + 1; j >= 0 && k < n && s[j] == s[k]; j--, k++) {
      int l = k - j + 1;
      if (l < n && maxl < l) maxl = l;
    }
    for (int j = i, k = i + 1; j >= 0 && k < n && s[j] == s[k]; j--, k++) {
      int l = k - j + 1;
      if (l < n && maxl < l) maxl = l;
    }
  }

  printf("%d\n", maxl);
  return 0;
}