What i'm doing wrong, using cv::Rodrigues?

[Aleksey Odynochenko]

I have two rotation matrices 

R1             R2         R3 

1 0 0         0 0 0      0 0 1 

0 0 -1   X   0 1 0 =   1 0 0 

0 1 0        -1 0 0      0 1 0 

R1 and R2 correspond the Euler angles: 

(90, 0 , 0) and (0, 0, 90) 

as a result, I expect to get a turn like this 

90, 0 , 90 

But cv::Rodrigues returns this angles : (69, 69, 69). 

What I'm doing wrong