The open loop transfer function of a unity negative feedback system is $$G(s) = {k \over {s(1 + s{T_1})(1 + s{T_2})}}$$, where $$k,T_1$$ and $$T_2$$ are positive constants. The phase cross-over frequency, in rad/s, is

A closed loop system is shown in the figure where $$k>0$$ and $$\alpha > 0$$. The steady state error due to a ramp input $$(R(s) = \alpha /{s^2})$$ is given by

In the following block diagram, R(s) and D(s) are two inputs. The output Y(s) is expressed as Y(s) = G$$_1$$(s)R(s) + G$$_2$$(s)D(s).

G$$_1$$(s) and G$$_2$$(s) are given by

The asymptotic magnitude Bode plot of a minimum phase system is shown in the figure. The transfer function of the system is $$(s) = {{k{{(s + z)}^a}} \over {{s^b}{{(s + p)}^c}}}$$, where $$k,z,p,z,b$$ and $$c$$ are positive constants. The value of $$(a + b + c)$$ is ___________ (rounded off to the nearest integer)