I am trying assignment of an Institute in which I am not a student and I am unable to think about this problem.
Problem If there exist integers $a$ and $b$ such that $(a, b) = 1$ and $1+ \frac{1}{2} + \ldots + \frac{1}{p-1} = \frac{a}{b}$ then prove that $p^2 | a$ , assuming that $p\geq 3$.
Can someone please help how to approach this problem.