#include <iostream>
#include <string>
#include <vector>
#include <unordered_map>
#include <unordered_set>

int main() {
    std::string S;
    std::cin >> S;
    
    std::unordered_set<char> alpha_set(S.begin(), S.end());
    
    // ruiseki[i][s]をS[:i]のアルファベットsの出現回数とする
    std::vector<std::unordered_map<char, int>> ruiseki(S.length() + 1);
    
    for (int i = 0; i < S.length(); ++i) {
        char A = S[i];
        int idx = i + 1;
        
        for (char MM : alpha_set) {
            ruiseki[idx][MM] = ruiseki[idx - 1][MM];
        }
        ruiseki[idx][A] += 1;
    }
    
    int ans = 0;
    for (int i = 0; i < S.length(); ++i) {
        char A = S[i];
        
        for (const auto& entry : ruiseki[i]) {
            char MM = entry.first;
            
            if (A == MM) {
                continue;
            }
            
            ans += ruiseki[i][MM] * (ruiseki[i][MM] - 1) / 2;
        }
    }
    
    std::cout << ans << std::endl;
    
    return 0;
}