#include <bits/stdc++.h>

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

    std::string s;
    std::cin >> s;

    std::vector<int> v;

    int qtd = 1;
    char last = '$';
    for (const char &c : s)
    {
        if (c == last)
        {
            qtd += 1;
        }
        else
        {
            v.push_back(qtd);
            qtd = 1;
            last = c;
        }
    }
    v.push_back(qtd);

    std::sort(v.rbegin(), v.rend());

    std::cout << (1LL * v[0] * v[1]) << std::endl;

    return 0;
}