#include<bits/stdc++.h>
using namespace std;
#define inf 0x3f3f3f3f
#define sz(x) int((x).size())
#define fi first
#define se second
typedef long long ll;
typedef pair<int, int> ii;
template<class X, class Y>
inline bool maximize(X &x, const Y &y) {return (x < y ? x = y, 1 : 0);}
template<class X, class Y>
inline bool minimize(X &x, const Y &y) {return (x > y ? x = y, 1 : 0);}
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int Random(int l, int r) {
return uniform_int_distribution<int>(l, r)(rng);
}
const bool isMultiTest = 0;
const int MAXN = 300005;
const int NMOD = 2;
const int MOD[] = {int(1e9) + 2277, int(1e9) + 5277, int(1e9) + 8277};
const int BASE = 256;
ll pw[NMOD][MAXN];
struct Hash {
ll value[NMOD];
Hash(char c = 0) {
for (int i = 0; i < NMOD; ++i)
value[i] = c;
}
Hash operator + (const Hash &h) const {
Hash res;
for (int i = 0; i < NMOD; ++i) {
res.value[i] = value[i] + h.value[i];
if(res.value[i] >= MOD[i])
res.value[i] -= MOD[i];
}
return res;
}
Hash operator - (const Hash &h) const {
Hash res;
for (int i = 0; i < NMOD; ++i) {
res.value[i] = value[i] - h.value[i];
if(res.value[i] < 0)
res.value[i] += MOD[i];
}
return res;
}
Hash operator * (int k) const {
Hash res;
for (int i = 0; i < NMOD; ++i)
res.value[i] = value[i] * pw[i][k] % MOD[i];
return res;
}
bool operator == (const Hash &h) const {
for (int i = 0; i < NMOD; ++i) {
if(value[i] != h.value[i])
return false;
}
return true;
}
} hashVal[MAXN], revHashVal[MAXN];
string str;
int Plcp[MAXN][19], cnt[MAXN], tmp[MAXN];
int P[2][MAXN][19], maxPalin[2][MAXN];
int sa[MAXN], pos[MAXN], lcp[MAXN], strLen;
int gap;
bool sufCmp(int i, int j) {
if(pos[i] != pos[j])
return (pos[i] < pos[j]);
return (max(i, j) + gap > strLen) ? (i > j) : (pos[i + gap] < pos[j + gap]);
}
void countsort(int gap) {
for (int i = 1; i <= max(256, strLen); ++i)
cnt[i] = 0;
for (int i = 1; i <= strLen; ++i)
++cnt[(i + gap <= strLen ? pos[i + gap] : 0)];
for (int i = 1; i <= max(256, strLen); ++i)
cnt[i] += cnt[i - 1];
for (int i = strLen; i > 0; --i)
tmp[cnt[(sa[i] + gap <= strLen ? pos[sa[i] + gap] : 0)]--] = sa[i];
for (int i = 1; i <= strLen; ++i)
sa[i] = tmp[i];
}
void buildSA(void) {
for (int i = 1; i <= strLen; ++i)
sa[i] = i, pos[i] = str[i];
for (gap = 1; gap <= strLen; gap <<= 1) {
countsort(gap);
countsort(0);
tmp[sa[1]] = 1;
for (int i = 2; i <= strLen; ++i)
tmp[sa[i]] = tmp[sa[i - 1]] + sufCmp(sa[i - 1], sa[i]);
for (int i = 1; i <= strLen; ++i)
pos[i] = tmp[i];
if(tmp[sa[strLen]] == strLen)
break;
}
}
void buildLCP(void) {
int k(0);
for (int i = 1; i <= strLen; ++i) {
if(pos[i] != strLen) {
for (int j = sa[pos[i] + 1]; str[i + k] == str[j + k]; ) ++k;
lcp[pos[i]] = k;
k -= (k > 0);
}
}
}
inline int getLCP(int l, int r) {
int log = 31 - __builtin_clz(r - l + 1);
return min(Plcp[l][log], Plcp[r - (1 << log) + 1][log]);
}
void init(void) {
for (int i = 0; i < NMOD; ++i) {
pw[i][0] = 1;
for (int j = 1; j < MAXN; ++j)
pw[i][j] = pw[i][j - 1] * BASE % MOD[i];
}
}
inline Hash getHash(int l, int r) {
return (hashVal[r] - hashVal[l - 1]) * (strLen - r);
}
inline Hash getRevHash(int l, int r) {
return (revHashVal[l] - revHashVal[r + 1]) * (l - 1);
}
inline int getMax(int P[][19], int l, int r) {
int log = 31 - __builtin_clz(r - l + 1);
return max(P[l][log], P[r - (1 << log) + 1][log]);
}
void process(void) {
cin >> str;
strLen = sz(str);
str = '^' + str;
buildSA();
buildLCP();
init();
for (int i = 1; i <= strLen; ++i)
hashVal[i] = hashVal[i - 1] + Hash(str[i]) * i;
for (int i = strLen; i > 0; --i)
revHashVal[i] = revHashVal[i + 1] + Hash(str[i]) * (strLen - i + 1);
for (int i = 1; i <= strLen; ++i) {
int l(1), r = min(i, strLen - i + 1), opt(0);
while(l <= r) {
int mid = (l + r) >> 1;
if(getHash(i - mid + 1, i) == getRevHash(i, i + mid - 1)) {
opt = mid;
l = mid + 1;
} else {
r = mid - 1;
}
}
maxPalin[0][i] = 2 * opt - 1;
if(i == strLen || str[i] != str[i + 1])
continue;
l = 1, r = min(i, strLen - i), opt = 0;
while(l <= r) {
int mid = (l + r) >> 1;
if(getHash(i - mid + 1, i) == getRevHash(i + 1, i + mid)) {
opt = mid;
l = mid + 1;
} else {
r = mid - 1;
}
}
maxPalin[1][i] = 2 * opt;
}
ll res(0);
for (int i = strLen; i > 0; --i) {
res = max(res, ll(max(maxPalin[0][i], maxPalin[1][i])));
P[0][i][0] = maxPalin[0][i] - 2 * i;
P[1][i][0] = maxPalin[1][i] - 2 * i;
Plcp[i][0] = lcp[i];
}
for (int j = 1; (1 << j) <= strLen; ++j) {
for (int i = 1; i + (1 << j) - 1 <= strLen; ++i) {
Plcp[i][j] = min(Plcp[i][j - 1], Plcp[i + (1 << (j - 1))][j - 1]);
for (int t = 0; t < 2; ++t)
P[t][i][j] = max(P[t][i][j - 1], P[t][i + (1 << (j - 1))][j - 1]);
}
}
stack<int> st;
for (int i = 2; i <= strLen; ++i) {
while(sz(st) && getLCP(st.top(), i - 1) >= lcp[i - 1]) {
int x(st.top()); st.pop();
int y = (sz(st)) ? st.top() : 0;
int lcpn = getLCP(x, i - 2);
int l(1), r(lcpn), opt(0);
while(l <= r) {
int mid = (l + r) >> 1;
int f(-2 * sa[x] - 1);
if(sa[x] + mid / 2 <= sa[x] + (lcpn - 1) / 2)
f = max(f, getMax(P[0], sa[x] + mid / 2, sa[x] + (lcpn - 1) / 2));
if(sa[x] + (mid - 1) / 2 <= sa[x] + lcpn / 2 - 1)
f = max(f, getMax(P[1], sa[x] + (mid - 1) / 2, sa[x] + lcpn / 2 - 1));
if(f + 2 * sa[x] > 0) {
opt = mid;
l = mid + 1;
} else {
r = mid - 1;
}
}
res = max(res, 1LL * opt * (i - y - 1));
//cout << i << ' ' << y << ' ' << x << ' ' << lcpn << '\n';
}
st.push(i - 1);
}
while(sz(st)) {
int x(st.top()); st.pop();
int y = (sz(st)) ? st.top() : 0;
int lcpn = getLCP(x, strLen - 1);
int l(1), r(lcpn), opt(0);
while(l <= r) {
int mid = (l + r) >> 1;
int f(-2 * sa[x] - 1);
if(sa[x] + mid / 2 <= sa[x] + (lcpn - 1) / 2)
f = max(f, getMax(P[0], sa[x] + mid / 2, sa[x] + (lcpn - 1) / 2));
if(sa[x] + (mid - 1) / 2 <= sa[x] + lcpn / 2 - 1)
f = max(f, getMax(P[1], sa[x] + (mid - 1) / 2, sa[x] + lcpn / 2 - 1));
if(f + 2 * sa[x] >= 0) {
opt = mid;
l = mid + 1;
} else {
r = mid - 1;
}
}
res = max(res, 1LL * opt * (strLen - y));
//cout << strLen + 1 << ' ' << y << ' ' << x << ' ' << lcpn << '\n';
}
cout << res << '\n';
}
int main(void) {
ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
#define TASK "palindrome"
if(fopen(TASK".inp", "r")) {
freopen(TASK".inp", "r", stdin);
freopen(TASK".out", "w", stdout);
}
int numTest = 1;
if(isMultiTest)
cin >> numTest;
while(numTest--)
process();
return 0;
}
