IL-GROSSMAN 2022 Problem 2

We call a sequence of length $n$ of zeros and ones a "string of length $n$ " and the elements of the same sequence "bits". Let $m,n$ be two positive integers so that $m<2^n$ . Arik holds $m$ strings of length $n$ . Giora wants to find a new string of length $n$ different from all those Arik holds. For this Giora may ask Arik questions of the form:

"What is the value of bit number $i$ in string number $j$ ?"

where $1\leq i\leq n$ and $1\leq j\leq m$ . What is the smallest number of questions needed for Giora to complete his task when:a) $m=n$ ?b) $m=n+1$ ?