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

class range {private: struct I{int x;int operator*(){return x;}bool operator!=(I& lhs){return x<lhs.x;}void operator++(){++x;}};I i,n;
public:range(int n):i({0}),n({n}){}range(int i,int n):i({i}),n({n}){}I& begin(){return i;}I& end(){return n;}};

bool is_palindrome(string s) { return equal(s.begin(), s.begin()+s.size()/2, s.rbegin()); }

int main(void) {
  string s; cin >> s;
  int n = s.size();
  int res = 0;
  for(int i : range(n)) {
    for(int j : range(i, n)) {
      if(i==0 && j==n-1) { continue; }
      string t = s.substr(i, j-i+1);
      if(is_palindrome(t)) {
        res = max(res, j-i+1);
      }
    }
  }
  printf("%d\n", res);
  return 0;
}