Let
be an integer. Find the maximal cardinality of a set
of pairs
of integers,
, with the following property: If
, then
for any
%V0
Let $n \geq 2$ be an integer. Find the maximal cardinality of a set $M$ of pairs $(j, k)$ of integers, $1 \leq j < k \leq n$, with the following property: If $(j, k) \in M$, then $(k,m) \not \in M$ for any $m.$
Školjka