std::string OptimalRates::getAskChain(Currency from, Currency to)
{
    size_t i = m_indexes[from];
    size_t j = m_indexes[to];
    size_t m = m_hop_number - 1;

    std::ostringstream oss;

    PDEBUG("XXX: Find bid chain from " << i << " to " << j);

    if (m_rates[m][i][j].isEmpty()) {
        PDEBUG("XXX: There is no path");
        return std::string("No cross rate");
    }

    size_t child = i;
    PDEBUG("XXX: child " << child);

    while (m >= 0 && m < m_hop_number) {
        if (m_children[m][child][j].getValue() != child) {
            oss << m_currencies[child] << "-";
        }

        child = m_children[m--][child][j].getValue();
        PDEBUG("XXX: child " << child);
    }

    oss << m_currencies[child];

    return oss.str();
}