Query: Greece's secondary education has how many school types?
Context: Greece's post-compulsory secondary education consists of two school types: unified upper secondary schools (Γενικό Λύκειο, Genikό Lykeiό) and technical–vocational educational schools (Τεχνικά και Επαγγελματικά Εκπαιδευτήρια, "TEE"). Post-compulsory secondary education also includes vocational training institutes (Ινστιτούτα Επαγγελματικής Κατάρτισης, "IEK") which provide a formal but unclassified level of education.