#include <bits/stdc++.h>

using namespace std;

#define rep(i, l, r) for (auto i = l; i < (r); i++)
using vi = vector<int>;

int sz(auto&& x) { return int(size(x)); }

array<vi, 2> manacher(const string& s) {
    int n = sz(s);
    array<vi,2> p = {vi(n+1), vi(n)};
    rep(z,0,2) for (int i=0,l=0,r=0; i < n; i++) {
        int t = r-i+!z;
        if (i<r) p[z][i] = min(t, p[z][l+t]);
        int L = i-p[z][i], R = i+p[z][i]-!z;
        while (L>=1 && R+1<n && s[L-1] == s[R+1])
            p[z][i]++, L--, R++;
        if (R>r) l=L, r=R;
    }
    return p;
}

string solve(string_view s) {
    auto lps = manacher(s.data());
    int l = 0;
    for (int i = 1; i < sz(s); i++) {
        if (lps[0][i] >= i - l) {
            l = i;
        }
    }
    return {begin(s) + l, end(s)};
}

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);

    string s;
    cin >> s;

    auto t = solve(s);
    ranges::reverse(t);
    cout << sz(solve(t)) << '\n';
}