7. Given $l_{1}, l_{2}, \cdots, l_{100}$ are 100 distinct and coplanar lines. If the lines numbered $4 k\left(k \in \mathbf{Z}_{+}\right)$ are parallel to each other, and the lines numbered $4 k-1$ all pass through point $A$, then the maximum number of intersection points of these 100 lines is $\qquad$ .
7.4351 .

According to the problem, the number of combinations of any two lines out of 100 lines is
$$
\mathrm{C}_{100}^{2}-\mathrm{C}_{25}^{2}-\mathrm{C}_{25}^{2}+1=4351 .
$$