#include <bits/stdc++.h>
using namespace std;
const int N = 300'000 + 10;
string s;
int n;
using ull = unsigned long long;
const int base = 19937;
ull h[N], rh[N], pw[N];
void initHash() {
pw[0] = 1;
for (int i = 1; i <= n; ++i) {
h[i] = h[i - 1] * base + s[i];
pw[i] = pw[i - 1] * base;
}
reverse(s.begin() + 1, s.end());
for (int i = 1; i <= n; ++i) rh[i] = rh[i - 1] * base + s[i];
reverse(s.begin() + 1, s.end());
}
ull get(int l, int r) { return h[r] - h[l - 1] * pw[r - l + 1]; }
ull rget(int l, int r) {
tie(l, r) = make_pair(n - r + 1, n - l + 1);
return rh[r] - rh[l - 1] * pw[r - l + 1];
}
bool chk(int l, int r) { return get(l, r) == rget(l, r); }
unordered_map<ull, long long> cnt;
int32_t main() {
cin.tie(0)->sync_with_stdio(0);
cin >> s;
n = s.size(); s = '@' + s;
initHash();
for (int i = 1; i <= n; ++i) {
for (int j = i; j <= n; ++j) if (chk(i, j)) cnt[get(i, j)] += j - i + 1;
}
long long answer = 0;
for (const auto& x : cnt) answer = max(answer, x.second);
cout << answer << "\n";
cerr << 1.0 * clock() / CLOCKS_PER_SEC << "\n";
}
