An under cover police is following a suspect. At each second, the suspect decides to stay at his current position with the probability of 'p' or move one unit for- ward/backward with the equal probability '(1-p)/2'. The police always moves one unit toward the suspect regardless of suspect's movement. Let's assume that the police is initially 'X' unit away from the suspect where X is a discrete random variable with PMF of Px(x). What is the expected value of the time it takes the police to capture the suspect?