Let $R$ denote the circular region in the $x y -$ plane bounded by the circle $x^{2} + y^{2} = 36$ . The lines $x = 4$ and $y = 3$ divide $R$ into four regions $R_{i}, i = 1, 2, 3, 4$ . If $|R_{i}|$ denotes the area of the region $R_{i}$ and if $|R_{1}| > |R_{2}| > |R_{3}| > |R_{4}|,$ determine $| R_{1} | - | R_{2} | - | R_{3} | + | R_{4} |$ . (Here $|Ω|$ denotes the area of the region $Ω$ in the plane)