options:
    max_hoppers: 32

variables:
    max.hoppers=0
    
on place of hopper:
    add 1 to {max.hoppers::%player%}
    if {max.hoppers::%player%} is higher than {@max_hoppers}:
        send "o" to player
        cancel event

on break of hopper:
    remove 1 from {max.hoppers::%player%}