CF870B Maximum of Maximums of Minimums

You are given an array $ a_{1},a_{2},...,a_{n} $ consisting of $ n $ integers, and an integer $ k $ . You have to split the array into exactly $ k $ non-empty subsegments. You'll then compute the minimum integer on each subsegment, and take the maximum integer over the $ k $ obtained minimums. What is the maximum possible integer you can get? Definitions of subsegment and array splitting are given in notes.

The first line contains two integers $ n $ and $ k $ ( $ 1

Print single integer — the maximum possible integer you can get if you split the array into $ k $ non-empty subsegments and take maximum of minimums on the subsegments.

A subsegment $ [l,r] $ ( $ l1 $ ) is $ k $ sequences $ (a_{l1},...,a_{r1}),...,(a_{lk},...,a_{rk}) $ . In the first example you should split the array into subsegments $ [1,4] $ and $ [5,5] $ that results in sequences $ (1,2,3,4) $ and $ (5) $ . The minimums are $ min(1,2,3,4)=1 $ and $ min(5)=5 $ . The resulting maximum is $ max(1,5)=5 $ . It is obvious that you can't reach greater result. In the second example the only option you have is to split the array into one subsegment $ [1,5] $ , that results in one sequence $ (-4,-5,-3,-2,-1) $ . The only minimum is $ min(-4,-5,-3,-2,-1)=-5 $ . The resulting maximum is $ -5 $ .