def hackerlandRadioTransmitters(x, k):
    t=0 #number of transmitters
    ind=0 #our location in Hackerland
    while ind<max(x): #Loops through the cities in list x
        if ind+1 not in x:
            ind+=1 #This makes sure we don’t place transmitters in places where there are no houses
        else:
            while ind+k+1 not in x:
                ind-=1 #This makes sure that the center is one of the houses
            t+=1 #Adds a transmitter
            ind+=(2*k+1) #skips all the locations where the transmitter is reached
    return t #returns the amount of of transmitters