$2500$
16. As shown in the figure, in the Cartesian coordinate system, draw a broken line starting from the origin $O$, where the coordinates of the break points are $A_{1}(1,0), A_{2}(1,1), A_{3}(-1,1), A_{4}(-1,-1), A_{5}(2,-1), \cdots \cdots$, when drawing to $A_{99}$, the total length of the broken line is $\qquad$