List the number of games that ended up with 5-0 in Greece.
5-0 is a score where FTHG = '5' and FTAG = '0'; Greece is a name of country; games refer to Div;
SELECT COUNT(T1.Div) FROM matchs AS T1 INNER JOIN divisions AS T2 ON T1.Div = T2.division WHERE T2.country = 'Greece' AND T1.FTHG = 5 AND T1.FTAG = 0