read -dx {a..e}{,y}
for i in {a..e};{
for j in {a..e};{((f=f/3*3))
for k in {a..e};{((f+=(j-i)*($k\y-$i\y)<($j\y-$i\y)*(k-i)))
}
}
}
NO
echo ${_[f/15]-YES}