### Instruction:
How many managers have Arsenal had?

### Input:
There have been twenty permanent and eight caretaker managers of Arsenal since 1897; Stewart Houston has managed the club in two separate spells as caretaker. The most successful person to manage Arsenal is Arsène Wenger, who won three Premier League titles, seven FA Cups and seven Community Shields between 1996 and 2018. Wenger is the club's longest-serving manager; he surpassed George Allison's record of 13 years in October 2009. Two Arsenal managers have died in the job – Herbert Chapman and Tom Whittaker.

### Response:
Arsenal have had twenty permanent and eight caretake managers.