168 If the line $l$ passes through point $A\left(\frac{1}{2}, \frac{1}{3}\right)$ and point $B\left(\frac{1}{4}, \frac{1}{5}\right)$, then the nearest lattice point on $l$ to point $A$ is $\qquad$.
$168(-2,-1)$. The equation of line $l$ is $y=(8 \cdot x+1) / 15$. Clearly, the lattice point $(-2,-1)$ lies on $l$, and when $x=-1,0,1,2,3$, $(8 \cdot x+1) / 15$ is not an integer, so the lattice point on $l$ that is closest to point $A$ is $(-2,-1)$.