$(3)$

Your job is to arrange $n$ naughty childres in a straight line, facing frant. You are given a list of $.$ Stataments of the form ; hates j$.4$ ; hates $j,$ then you do not want to put i sanewhere, behind $j$ because than $i$ is capeble of throwing sauething at j$\mathrm{.}1.($Even if there are other children in between.$)$

Give on alforithm that orders the line in $O(m+n)$ time.

Note: Please do the full selution, for exauple, draw graphs.