The Incas valued the COCA leaf, which is a four-letter word. The COCA leaf was used by the Incas for medicinal and religious purposes. It was also used as a form of currency and was highly valued in Incan society. The leaves were chewed to produce a mild stimulant effect and were believed to have healing properties. The Incas also believed that the COCA leaf had spiritual powers and could be used to communicate with the gods.