//InTheNameOfGOD //PRS;) #pragma GCC optimize("O3,no-stack-protector,unroll-loops") #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2") #include<bits/stdc++.h> #define rep(i, l, r) for(ll i = ll(l); i < ll(r); ++i) #define per(i, l, r) for(ll i = ll(r) - 1; i >= ll(l); --i) #define Fast cin.tie(0) -> sync_with_stdio(0); #define min(x, y) (x < y ? x : y) #define max(x, y) (x > y ? x : y) typedef long long ll; using namespace std; constexpr int xn = 3e5 + 5; int ng[xn][26], ans[xn], lk[xn], oc[xn], sz[xn], cnt, ti; string s; inline void ad(int v) { while(s[v - sz[ti] - 1] != s[v]) ti = lk[ti]; int x = lk[ti], c = s[v] - 'a'; while(s[v - sz[x] - 1] != s[v]) x = lk[x]; if(!ng[ti][c]) { ng[ti][c] = ++cnt, sz[cnt] = sz[ti] + 2, lk[cnt] = sz[cnt] == 1 ? 2 : ng[x][c]; ans[cnt] = ans[lk[cnt]] + 1; } ti = ng[ti][c], oc[ti]++; } int main() { Fast cin >> s; int n = s.size(); lk[1] = lk[2] = 1, cnt = ti = 2, sz[1] = -1, sz[2] = 0; rep(i, 0, n) ad(i); per(i, 1, cnt + 1) oc[lk[i]] += oc[i]; ll ans = 0; rep(i, 2, cnt + 1) ans = max(ans, 1ll * oc[i] * sz[i]); cout << ans << '\n'; }