#include <algorithm>
#include <cstdio>
#include <cstdlib>
#include <cctype>
#include <cmath>
#include <iostream>
#include <queue>
#include <list>
#include <stack>
#include <map>
#include <numeric>
#include <set>
#include <sstream>
#include <string>
#include <vector>
using namespace std;
#define REP(i,a,n) for(int i=(a); i<(int)(n); i++)
#define rep(i,n) REP(i,0,n)
#define FOR(it,c) for(__typeof((c).begin()) it=(c).begin(); it!=(c).end(); ++it)
#define ALLOF(c) (c).begin(), (c).end()
typedef long long ll;

bool check(const string& str){
  rep(i,str.length()){
    if(str[i] != str[str.length()-1-i]) return false;
  }
  return true;
}

int main(){
  string S;
  cin >> S;

  int mx = 0;
  rep(i,S.length()){
    REP(j,i,S.length()){
      if(check(S.substr(i, j-i+1))){
        if(j-i+1 == S.length()) continue;
        mx = max(mx, j-i+1);
      }
    }
  }

  cout << mx << endl;
  
  return 0;
}