Given the graph of the function `y=f(x)`, draw the graph of `y ="sgn"(x)`.

Explanation

x = 1, 4, 6 are the points of local maxima, and the local maximum values are ` f(1) = 2, f(4) = 4 and f(6) = 3`.
x = 5, 7 are the points of local minima, and the local minimum values are ` f(5) = 2, f(7) = 1` .
x = 2 is the point of absolute minima and the local minimum value is f(2) = 0.
x = 8 is the point of absolute maxima and the absolute maximum value is f (4) = 5.