Codeforce121(Div2.B)

gistfile1.rb

n = gets.chomp.to_i
a = gets.chomp.split(" ").map{|e| e.to_i}

days = 0
loop do
  break if a[0] == 0 or a[-1] == 0
  
  bang = false
  for i in 1 .. (n - 2) do
    bang = true if a[i] == 0 and a[i + 1] == 0
  end
  break if bang
  
  days += 1
 
  a.map!{|e|
    e > 0 ? e -= 1 : e
  }  
end

puts days