summon area_effect_cloud ^ ^ ^0.5 {Tags:[Select],Particle:"block air"}
execute store result score Y Temp run data get entity @e[tag=Select,limit=1] Pos[1] 2
scoreboard players add Depth Temp 1
kill @e[tag=Select]
execute if score Y Temp <= 21 Integer run tag @e[tag=Board,tag=!Unused,sort=nearest,limit=1] add Selected
execute if score Depth Temp > 100 Integer run tag @e[tag=Board,tag=!Unused,sort=nearest,limit=1] add Selected
execute unless score Y Temp <= 21 Integer unless score Depth Temp > 100 Integer positioned ^ ^ ^0.5 run function main:select