Consider the function f(x) = x / 2 if x is even and f(x) = 3x + 1 if x is odd.
Now construct a sequence of integers by taking an intial positive integer and repeating this function where output of a step is the input of the next step.
The Collatz conjecture is: This process will eventually reach the number 1, regardless of which positive integer is chosen initially.
For example, if initial input is 11 then we get: 11, 34, 17, 52, 26, 13, 40, 20, 10, 5, 16, 8, 4, 2, 1.

After taking an initial positive integer value, construct a ling graph by plotting number of steps k on x-axis and and value of f(k) on y-axis.