Write a function solution that, given a string S of length N$,$ returns the length of the shortest unique substring of S$,$ that is$,$ the length of the shortest word which occurs in S exactly once.Examples:$1.$ Given S $="$baaba$",$ the function should return $2.$The shortest unique substring of S is $"$aa$"\mathrm{.}2.$ Given S $="$zyzyzyz$",$ the function should return $5.$The shortest unique substring of S is $"$yzyzy$".$ Note that there are shorter words, like $"$yzy$",$ occurrences of which overlap, but they still count as multiple occurrences$\mathrm{.}3.$ Given S $=$ "aabbbabaaa", the function should return $3.$ All substrings of size $2$ occurs in S at least twice.Assume that:$*$ N is an integer within the range $[1\mathrm{.}200]$;$*$ string S is made only of lowercase letters $($a$-$z$).$In your solution, focus on correctness. The performance of your solution will not be the focus of the accessment