#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i, n) for(ll i = 0, i##_len = (n); i < i##_len; i++)
#define reps(i, s, n) for(ll i = (s), i##_len = (n); i < i##_len; i++)
#define rrep(i, n) for(ll i = (n) - 1; i >= 0; i--)
#define rreps(i, e, n) for(ll i = (n) - 1; i >= (e); i--)
#define all(x) (x).begin(), (x).end()
#define sz(x) ((ll)(x).size())
#define len(x) ((ll)(x).length())

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    // ifstream in("input.txt");
    // cin.rdbuf(in.rdbuf());
    string s;
    cin >> s;
    ll n = len(s);
    ll ans = 1;
    rep(i, n) {
        ll left = i, right = n - 1 - i;
        ll tmp = 1;
        reps(j, 1, min(left, right) + 1) {
            if (s[i - j] == s[i + j]) {
                tmp += 2;
            }
        }
        ans = max(ans, tmp);
        if ((i == (n - 1)) || (s[i] != s[i + 1])) continue;
        left = i, right = n - 2 - i;
        tmp = 2;
        reps(j, 1, min(left, right) + 1) {
            if (s[i - j] == s[i + j]) {
                tmp += 2;
            }
        }
        ans = max(ans, tmp);
    }
    cout << ans << endl;
    return 0;
}