3.3. On the base $AB$ of isosceles triangle $ABC$, a point $E$ is taken, and circles are inscribed in triangles $ACE$ and $ECB$, touching segment $CE$ at points $M$ and $N$. Find the length of segment $MN$, if the lengths of segments $AE$ and $BE$ are known.
3.3. According to problem $3.2 C M=(A C+C E-A E) / 2$ and $C N=(B C+C E-B E) / 2$. Considering that $A C=B C$, we get $M N=|C M-C N|=|A E-B E| / 2$.