Russian ⇄ English

на удивление трудны stresses
amer.	son of a bitch (used to express surprise or disappointment: The test turned out to be a real son of a bitch. Val_Ships)
на удивление трудный
amer.	real son of a bitch (used to express surprise or disappointment: The test turned out to be a real son of a bitch. Val_Ships)