This is the 4658th most frequent Russian word.
долгосрочный
Long-term.
The word 'долгосрочного' is used as an adjective modifying the noun 'планирования', describing the characteristic of the planning as being for the long term.
Этот проект требует долгосрочного планирования.
This project requires long-term planning.
Here, 'долгосрочная' is an adjective in the nominative case agreeing with the noun 'инвестиция', expressing the enduring nature of the investment.
Обучение языкам – это долгосрочная инвестиция.
Learning languages is a long-term investment.
In this example, 'долгосрочные' is an adjective in the plural form modifying the noun 'последствия', indicating that the consequences span or occur over a long period.