Something missing with NLTK and tokenize

Something missing with NLTK and tokenize

this is a part of my code where I try to tokenize a greek paragraph.
doc = "Ï õðïõñãüò Ïéêïíïìéêþí ÃéÜííçò ÓôïõñíÜñáò äéáâßâáóå ôçí ÔåôÜñôç
óôïí ðñüåäñï ôçò áñìüäéáò Áñ÷Þò êáôÜ ôïõ îåðëýµáôïò µáýñïõ ÷ñÞµáôïò,
Ðáíáãéþôç Íéêïëïýäç, ôï áßôçìá ôïõ õðïõñãïý Õãåßáò Áäùíé ÃåùñãéÜäç ãéá
êáôÜ ðñïôåñáéüôçôá Ýëåã÷ï ôïõ «ðüèåí Ýó÷åò» ôùí äéïéêçôþí êáé õðïäéïéêçôþí
ðïõ õðçñÝôçóáí óôï Åèíéêü Óýóôçìá Õãåßáò áðü ôï 2000 Ýùò êáé óÞìåñá."
tokens = nltk.WordPunctTokenizer().tokenize(doc)
The result is missing of few words for example "Áñ÷Þò" or "Ýó÷åò".
If I use this online tool for the same tokenize module, the words are
still there.
online tool
What I have understant until now is that after this code, I have another
line where I remove all words with < 3 characters.
And if I print the tokens, the word "Ýó÷åò" for example tokenized as
["Ý","ó÷","åò"]. Why those words tokenized too? I thought that this module
split sentences into the words.