Tamika studies at the coffee shop around the corner, at the same time that Lauren talks loudly on her cell phone. The costs and benefits of each cell phone call made by Lauren are given by the following table:

Number of cell phone calls

Marginal costs to Tamika

Marginal benefits to Lauren

$0$

$$0$

$$0$

$1$

$$4$

$$20$

$2$

$$12$

$$16$

$3$

$$20$

$$12$

If Tamika and Lauren can$$t negotiate a settlement without transactions costs, how many phone calls would Lauren end up making if she $($Lauren$)$ had the rights to make any calls she liked at the coffee shop?