Problem: In the provided layout, a $6-$inch slab is supported by beams positioned along gridlines $1,2,$ and $3.$ The applied live load on the slab is $100l\frac{b}{f}{t}^2.$ The beams have dimensions of $15$ inches by $18$ inches, and the entire structure is upheld by nine columns of equal strength, each measuring $20$ inches by $20$ inches. Each column can withstand a maximum load of $33150$ pounds. Given that the distance between gridlines $A-B$ and $B-C$ is assumed to be equal, what is the maximum spacing permissible between column lines A and $B($designated as I in the layout$)$ to ensure that the load does not surpass the columns' capacity? It is assumed that the density of concrete is $145I\frac{b}{f}{t}^3.$ Give your answer in a whole number.

Figure $1$: Building Top View