#pragma GCC optimize(2)

#pragma GCC optimize(3)

#pragma GCC optimize(4)

#include<bits/stdc++.h>

using namespace std;

#define y1 y11

#define fi first

#define se second

#define pi acos(-1.0)

#define LL long long

//#define mp make_pair

#define pb push_back

#define ls rt<<1, l, m

#define rs rt<<1|1, m+1, r

#define ULL unsigned LL

#define pll pair<LL, LL>

#define pli pair<LL, int>

#define pii pair<int, int>

#define piii pair<pii, int>

#define pdd pair<double, double>

#define mem(a, b) memset(a, b, sizeof(a))

#define debug(x) cerr << #x << " = " << x << "\n";

#define fio ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);

//head

const int N = 3e5 + ;

int p[N];

int manacher(string s) {

    string t = "$#";

    for (int i = ; i < s.size(); ++i) {

        t += s[i];

        t += '#';

    }

    int mx = , id = , resl = , resc = ;

    for (int i = ; i < t.size(); ++i) {

        p[i] = mx > i ? min(p[*id-i], mx-i) : ;

        while(t[i+p[i]] == t[i-p[i]]) ++p[i];

        if(mx < i+p[i]) mx = i+p[i], id = i;

        if(resl < p[i]) resl = p[i], resc = i;

    }

    return resl-;

}

int main() {

    string s;

    while(cin >> s) {

        cout << manacher(s) << endl;

    }

    return ;

}