Find the general solution $\sec^2x\;\tan y\;dx+\sec^2y\;\tan x\;dy=0$

Question

$\begin{array}{1 1} \tan y \tan x = C \\ \Large\frac{\tan y}{\tan x} = \normalsize C \\ \Large\frac{\tan x}{\tan y} = \normalsize C \\1 - \Large\frac{\tan y}{\tan x} = \normalsize C\end{array} $