#include <iostream>
#include <algorithm>
#include <cstring>

typedef long long ll;
typedef double lf;

// #define DEBUG 1
struct IO
{
    #define MAXSIZE (1 << 20)
    #define isdigit(x) (x >= '0' && x <= '9')
    char buf[MAXSIZE], *p1, *p2;
    char pbuf[MAXSIZE], *pp;
    #if DEBUG
    #else
    IO() : p1(buf), p2(buf), pp(pbuf) {}
    ~IO() {fwrite(pbuf, 1, pp - pbuf, stdout);}
    #endif
    #define gc() (p1 == p2 && (p2 = (p1 = buf) + fread(buf, 1, MAXSIZE, stdin), p1 == p2) ? ' ' : *p1++)
    #define blank(x) (x == ' ' || x == '\n' || x == '\r' || x == '\t')

    template <typename T>
    void Read(T &x)
    {
        #if DEBUG
        std::cin >> x;
        #else
        bool sign = 0; char ch = gc(); x = 0;
        for (; !isdigit(ch); ch = gc())
            if (ch == '-') sign = 1;
        for (; isdigit(ch); ch = gc()) x = x * 10 + (ch ^ 48);
        if (sign) x = -x;
        #endif
    }
    void Read(char *s)
    {
        #if DEBUG
        std::cin >> s;
        #else
        char ch = gc();
        for (; blank(ch); ch = gc());
        for (; !blank(ch); ch = gc()) *s++ = ch;
        *s = 0;
        #endif
    }
    void Read(char &c) {for (c = gc(); blank(c); c = gc());}

    void Push(const char &c)
    {
        #if DEBUG
        putchar(c);
        #else
        if (pp - pbuf == MAXSIZE) fwrite(pbuf, 1, MAXSIZE, stdout), pp = pbuf;
        *pp++ = c;
        #endif
    }
    template <typename T>
    void Write(T x)
    {
        if (x < 0) x = -x, Push('-');
        static T sta[35];
        int top = 0;
        do sta[top++] = x % 10, x /= 10; while (x);
        while (top) Push(sta[--top] ^ 48);
    }
    template <typename T>
    void Write(T x, char lst) {Write(x), Push(lst);}
} IO;
#define Read(x) IO.Read(x)
#define Write(x, y) IO.Write(x, y)
#define Put(x) IO.Push(x)

using namespace std;

const int MAXN = 3e5 + 10;

int n, m;
ll ans;
char s[MAXN];

int sa[MAXN], rk[MAXN], p[MAXN << 1], cnt[MAXN], ht[MAXN];
int lb[MAXN], rb[MAXN], st[MAXN], top;

int pl[MAXN], id[MAXN];

int tr[MAXN << 2];
inline void Pushup(int cur) {tr[cur] = max(tr[cur << 1], tr[cur << 1 | 1]);}
void Update(int cur, int l, int r, int x)
{
    if (l == r) tr[cur] = x;
    else
    {
        int mid = l + r >> 1;
        if (x <= mid) Update(cur << 1, l, mid, x);
        else Update(cur << 1 | 1, mid + 1, r, x);
        Pushup(cur);
    }
}
int Query(int cur, int l, int r, int x)
{
    if (x <= 0) return -1;
    if (r <= x) return tr[cur];
    int mid = l + r >> 1, res = Query(cur << 1, l, mid, x);
    if (x > mid) res = max(res, Query(cur << 1 | 1, mid + 1, r, x));
    return res;
}

int main()
{
    #if DEBUG
    #else
    ios::sync_with_stdio(0), cin.tie(0);
    #endif
    Read(s + 1), n = strlen(s + 1);
    m = 127;
    for (int i = 1; i <= n; i++) cnt[rk[i] = s[i]]++;
    for (int i = 2; i <= m; i++) cnt[i] += cnt[i - 1];
    for (int i = 1; i <= n; i++) sa[++cnt[rk[i] - 1]] = i;
    for (int w = 1; w <= n; w <<= 1)
    {
        int top = 0;
        for (int i = n - w + 1; i <= n; i++) p[++top] = i;
        for (int i = 1; i <= n; i++)
            if (sa[i] > w) p[++top] = sa[i] - w;
        memset(cnt, 0, sizeof(cnt));
        for (int i = 1; i <= n; i++) cnt[rk[i]]++;
        for (int i = 2; i <= m; i++) cnt[i] += cnt[i - 1];
        for (int i = 1; i <= n; i++) sa[++cnt[rk[p[i]] - 1]] = p[i];
        memcpy(p, rk, sizeof(rk));
        m = 0;
        for (int i = 1; i <= n; i++)
            rk[sa[i]] = (p[sa[i]] == p[sa[i - 1]] && p[sa[i] + w] == p[sa[i - 1] + w] ? m : ++m);
        if (m == n) break;
    }
    for (int i = 1, j = 0; i <= n; i++)
    {
        if (rk[i] == 1) continue;
        if (j) j--;
        while (i + j <= n && sa[rk[i] - 1] + j <= n && s[i + j] == s[sa[rk[i] - 1] + j]) j++;
        ht[rk[i]] = j;
    }
    // lb[i] -> rk[i] leftbound
    st[top = 1] = 1;
    for (int i = 2; i <= n; i++)
    {
        while (top > 1 && ht[st[top]] >= ht[i]) top--;
        lb[i] = st[top], st[++top] = i;
    }
    st[top = 1] = n + 1;
    for (int i = n; i >= 2; i--)
    {
        while (top > 1 && ht[st[top]] >= ht[i]) top--;
        rb[i] = st[top] - 1, st[++top] = i;
    }
    // for (int i = 1; i <= n; i++) cout << lb[i] << " "; cout << "\n";
    // for (int i = 1; i <= n; i++) cout << rb[i] << " "; cout << "\n";

    for (int i = 1, l = 0, r = 0; i <= n; i++)
    {
        pl[i] = (i > r ? 0 : min(pl[l + r - i], r - i));
        while (i + pl[i] < n && i - pl[i] > 1 && s[i + pl[i] + 1] == s[i - pl[i] - 1]) pl[i]++;
        if (i + pl[i] > r) l = i - pl[i], r = i + pl[i];
        ans = max(ans, pl[i] * 2ll + 1);
    }
    // for (int i = 1; i <= n; i++) cout << pl[i] << " "; cout << "\n";
    for (int i = 1; i <= n; i++) id[i] = i;
    sort(id + 1, id + n + 1, [&](int x, int y) {return x - pl[x] < y - pl[y];});
    memset(tr, -1, sizeof(tr));
    for (int i = 1, j = 1; i <= n; i++)
    {
        if (rk[i] == 1 || ht[rk[i]] == 0) continue;
        while (j <= n && id[j] - pl[id[j]] <= i) Update(1, 1, n, id[j]), j++;
        int cur = Query(1, 1, n, i + (ht[rk[i]] - 1) / 2);
        if (cur >= i) ans = max(ans, (ll)(2 * cur - 2 * i + 1) * (rb[rk[i]] - lb[rk[i]] + 1));
    }

    for (int i = 1, l = 0, r = 0; i <= n; i++)
    {
        pl[i] = (i > r ? -1 : min(pl[l + r - i - 1], r - i - 1));
        while (i + pl[i] + 1 < n && i - pl[i] > 1 && s[i + pl[i] + 2] == s[i - pl[i] - 1]) pl[i]++;
        if (i + pl[i] + 1 > r) l = i - pl[i], r = i + pl[i] + 1;
        ans = max(ans, pl[i] * 2ll + 2);
    }
    for (int i = 1; i <= n; i++) id[i] = i;
    sort(id + 1, id + n + 1, [&](int x, int y) {return x - pl[x] < y - pl[y];});
    memset(tr, -1, sizeof(tr));
    for (int i = 1, j = 1; i <= n; i++)
    {
        if (rk[i] == 1 || ht[rk[i]] == 0) continue;
        while (j <= n && id[j] - pl[id[j]] <= i) Update(1, 1, n, id[j]), j++;
        int cur = Query(1, 1, n, i - 1 + ht[rk[i]] / 2);
        if (cur >= i) ans = max(ans, (ll)(2 * cur - 2 * i + 2) * (rb[rk[i]] - lb[rk[i]] + 1));
    }
    Write(ans, '\n');
    return 0;
}