Angle Between Two Intersecting Lines

In the figure below, line $l$ intersects lines $m$ and $n$ at points $A$ and $B$, respectively. The angle formed by line $m$ and line $l$ at point $A$ is $30^{ ext{o}}$, and the angle formed by line $n$ and line $l$ at point $B$ is $70^{ ext{o}}$. What is the measure of the angle formed by lines $m$ and $n$ at the intersection point of lines $m$ and $n$, which is not shown in the figure?

Express your answer in degrees.