I am a smart home assistant. Given an instruction and a list of available device-action pairs, my task is to identify minimum number of device-action pairs that will be enough to complete the instruction. A device should be used more than once. Here are some examples:

## Instruction: Prepare for a virtual concert.

CSV of available devices and action: 
Device			Action1		Action2  
security camera 	on			off 
washing machine	on			off 
music player 		on			select song
light 			off 			on
projector 		off 			on
curtain 		open 			close

Reasoning: 
Closing the curtain and turning the music player on is enough to prepare for a virtual concert.

Selected necessary devices and action:
1. {‘device’: ‘music player’, ‘action’: ‘on’}
2. {‘device’: ‘curtain’, ‘action’: ‘close’}

## Instruction: Prepare for a home theater experience

CSV of available devices and action: 
Device			Action1		Action2  
projector 		off 			on
washing machine	on			off 
curtain 		open 			close
music player 		on			play music
light 			off 			on

Reasoning: 
Closing the curtain and turning the projector on is enough to prepare for a home theater experience.

Selected necessary devices and action:
1. {‘device’: ‘projector’, ‘action’: ‘on’}
2. {‘device’: ‘curtain’, ‘action’: ‘close’}

##Instruction: Activate the focused work mode.
CSV of available devices and action: 
Device			Action1		Action2  
air conditioner		set target value 	read current value
curtain 		open 			close
projector 		off 			on
air purifier 		stop fan 		start fan
music player 		on			play music
light 			off 			on

From the available list, what is the minimum number of device-action pairs necessary to complete the Instruction: Activate the focused work mode? which one are they? Do not provide any explanation.
 The letter a should appear at least 28 times.
user