#!/usr/bin/ruby
def value(n : Int32, a : Array(Int32))
	idxes=Hash(Int32,Int32).new
	a.each_with_index{|e,i|idxes[e]=i}
	ret=0
	1.upto(n-1){|i|
		idxi=idxes[i]
		(i+1).upto(n){|j|
			idxj=idxes[j]
			r=0
			(0..n-1).each{|idxk|
				next if idxk==idxi || idxk==idxj
				b=[[idxi,i],[idxj,j],[idxk,a[idxk]]].sort.map{|e|e[1]}
				if (b[0]<b[1]&&b[2]<b[1]) || (b[0]>b[1]&&b[2]>b[1])
					r=[r,a[idxk]].max
				end
			}
			ret+=[r,i,j].max if r>0
		}
	}
	ret
end
n,m=gets.not_nil!.split.map(&.to_i)
p (0..m-1).max_by{|i|value(n,gets.not_nil!.split.map(&.to_i))}