#include<iostream>
#include<math.h>
#include<vector>
#include <array>
#include <algorithm>
#include <queue>
#include <numeric>
#include <map>

using namespace std;
#define int long long
#define FOR(i, a, b) for(int i=(a);i<(b);i++)
#define RFOR(i, a, b) for(int i=(b-1);i>=(a);i--)
#define REP(i, n) for(int i=0; i<(n); i++)
#define RREP(i, n) for(int i=(n-1); i>=0; i--)
#define ALL(a) (a).begin(),(a).end()
#define UNIQUE_SORT(l) sort(ALL(l)); l.erase(unique(ALL(l)), l.end());
#define CONTAIN(a, b) find(ALL(a), (b)) != (a).end()
#define array2(type, x, y) array<array<type, y>, x>
#define vector2(type) vector<vector<type> >
#define out(...) //printf(__VA_ARGS__)

typedef pair<int, int> pos;
int pos::*x = &pos::first;
int pos::*y = &pos::second;

int dxy[] = {0, 1, 0, -1, 0};

/*================================*/

bool isKaibun(string s) {
    if (s.size() == 0) return false;
    REP(i,s.size()/2) {
        if (s[i] != s[s.size() - 1 - i]) return false;
    }
    return true;
}

map<string, int> cache;

int maxlen(string s, int num) {
    if (cache[s]) return cache[s];
    vector<int> poss;
    FOR(i,0,s.size()+1) {
        string t = s.substr(0,i);
        if (isKaibun(t)) {
            poss.push_back(i);
        }
    }
    int maxl = 0;
    for (int pos : poss) {
        string t = s.substr(0, pos);
        string u = s.substr(pos);
        if (u.size() == 0) {
            if (num > 0) {
              maxl = max(maxl, (int)t.size());
              //cout << maxl << ":" << t << endl;
            }
        } else { // 後も回文の必要あり
            int l = maxlen(u, num+1);
            if (l == 0) continue;
            maxl = max(max(maxl, l), (int)t.size());
            //cout << maxl << ":" << s << "=" << t << "+" << u << endl;
        }
    }
    //cout << s << ":" << maxl << endl;
    cache[s] = maxl;
    return maxl;
}

signed main()
{
    string s;
    cin >> s;

    cout << maxlen(s, 0) << endl;

    return 0;
}