#include <bits/stdc++.h>

using namespace std;
typedef long long ll;
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<ll> VL;
typedef vector<VL> VVL;
typedef pair<int, int> PII;

#define FOR(i, a, n) for (ll i = (ll)a; i < (ll)n; ++i)
#define REP(i, n) FOR(i, 0, n)
#define ALL(x) x.begin(), x.end()
#define MOD 1000000007
#define INF (1LL<<25)     //33554432
#define PI 3.14159265359
#define EPS 1e-12
//#define int ll

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

  int ret = -INF;
  REP(i, n) {
    FOR(j, i, n) {
      if(i == 0 && j == n-1) continue;
      if(i == j) {
        ret = max(ret, 1);
        continue;
      }
      int sz = j-i+1;
      bool flag = true;
      //cout << "i:" << i << " j:" << j << endl;
      FOR(k, i, i+sz/2) {
        if(s[k] != s[j-k+i]) flag = false;
      }
      if(flag) {
        //cout << i << " " << j << " " << sz << endl;
        ret = max(ret, sz);
      }
    }
  }

  cout << ret << endl;
  return 0;
}