String Paths

$Striver$ wants to strive hard in order to reach his goals, hence asks his mentor to give him a question for which he has to strive hard. The mentor gives $Striver$ a $N$ X $N$ matrix consisting of lowercase characters ($'a'$ to $'z'$) and $Q$ queries. Every query consists of $X$ and $Y$. From any position in the matrix, one can either move towards the right or towards down. He asks striver to w