#include <iostream>

#include <string>

int main() {
    std::string letters;
    std::cin >> letters;

    unsigned int balanced = 0;
    for(int i = 0; i < letters.length(); ++i) {
        int letter_usage[3] = { 0, 0, 0 };
        for(int j = i; j < letters.length(); ++j) {
            int idx = letters[j] - 'a';
            ++letter_usage[idx];
            
            int count = 0;
            for(int k = 0; k < 3; ++k) {
                if(letter_usage[k] == 0) continue;
                if(count == 0) count = letter_usage[k];
                if(count != letter_usage[k]) goto next;
            }
            ++balanced;
        next:;
        }
    }
    std::cout << balanced;
    return 0;
}