Filtering within a function

Attempting to create a filtered value by editing the formula. 

I want to see Count of total people for where risk is high.

• Field 1: People (All peoples name linked to a risk group)
• Field 2: Risk Group (High, Medium, Low) 

COUNT([People], [Risk_Group])

I right click on field [Risk_Group] then I edit the filter for the field as High.

But I get a Syntax Error: