mō bu zháo
unable to clearly understand (a situation etc)
mō bu zháo tóu nǎo
to be unable to make any sense of the matter
to be at a loss
zhàng èr hé shang , mō bu zháo tóu nǎo
lit. like a three-meter high monk, you can't rub his head (idiom)
fig. at a total loss
zhàng èr Jīn gāng mō bu zháo tóu nǎo
see 丈二和尚,摸不著頭腦|丈二和尚,摸不着头脑[zhang4 er4 he2 shang5 , mo1 bu5 zhao2 tou2 nao3]