#include <iostream>
#include <string>
#include <cmath>
#include <vector>

using namespace std;

string raw;
vector<char> rev;


int main()
{
  getline(cin, raw);
  for (int i = raw.size() - 1; i >= 0; --i) {
    rev.push_back(raw[i]);
  }

  int j = raw.size() - 1;
  for (int i = 0; i <= j; ++i) {
    if (raw[i] == raw[j]) {
      bool is_ok = true;
      for (int q = i, l = 0; q <= i + (j - i + 1) / 2; ++q, ++l) {
        if (raw[q] != rev[l])
          is_ok = false;
      }
      if (is_ok) {
        cout << i;
        break;
      }
    }
  }
}