The next two questions refer to the following fictional financial statement from Sharpie Markers, who sells their markers directly to consumers for $2/marker.

Revenue: $500,000

Plastic: $200,000

Ink: $1,000

Advertising: $5,000

Overhead: $1,000

Depreciation: $25

How many additional pens would Sharpie have to sell to maintain their current contribution to the organization if they invest $25,000 in advertising?