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#include <array>
#include <iostream>
#include <string>

int main()
{
    std::ios_base::sync_with_stdio(0);

    std::string w;
    std::getline(std::cin, w);

    size_t result = 0;
    std::array<int, 3> counts = {0, 0, 0};

    for (size_t start_idx = 0; start_idx < w.size(); ++start_idx)
    {
        counts = {0, 0, 0};
        counts[w[start_idx] - 'a'] = 1;
        ++result; // Single letter is always ok.
        if (start_idx + 1 < w.size())
        {
            // Two-letter is always ok.
            ++counts[w[start_idx + 1] - 'a'];
            ++result;
        }

        for (size_t end_idx = start_idx + 2; end_idx < w.size(); ++end_idx)
        {
            const char c = w[end_idx];
            ++counts[c - 'a'];

            bool is_ok = true;
            int expected_count = counts[w[start_idx] - 'a'];
            for (int x : counts)
            {
                if (x != 0 && x != expected_count)
                {
                    is_ok = false;
                    break;
                }
            }
            if (is_ok)
            {
                result += 1;
            }
            // std::cerr << "start=" << start_idx << ",end=" << end_idx << ",ok=" << is_ok << std::endl;
            // if (start_idx == 1 && end_idx == 2) {
            //     // std::cerr << "start_counts=" << start_counts[0] << ',' << start_counts[1] << ',' << start_counts[2] << std::endl;
            //     std::cerr << "counts=" << counts[0] << ',' << counts[1] << ',' << counts[2] << std::endl;
            // }
        }
    }

    std::cout << result << std::endl;
}