A particle starts to travel from a point P on the curve `C_1:|z-3-4i|=5`, where `|z|` is maximum. Form P, the particle moves through an angle `tan^-1 (3/4)` in anticlockwise direction on `|z-3-4i|=5` and reaches at point Q. From Q it comes down parallel to imaginary axis by 2 units and reachpoint R. Find the complex number corresponding to point R in the Argand plane.