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Numbers that are greater than all its right\left neighbours

Source: VI Caucasus Mathematical Olympiad

March 14, 2021
combinatorics

Problem Statement

Integers from 1 to 100 are placed in a row in some order. Let us call a number large-right, if it is greater than each number to the right of it; let us call a number large-left, is it is greater than each number to the left of it. It appears that in the row there are exactly kk large-right numbers and exactly kk large-left numbers. Find the maximal possible value of kk.