N = gets.chomp.to_i
T,A = gets.chomp.split(" ").map(&:to_i)
heights = gets.chomp.split(" ").map(&:to_i)
min_ave_temp = 100000000
min_ave_num = 0

heights.each_with_index do |height, i|
  ave_temp = T - height*0.006
  ave_temp_diff = ave_temp - A
  ave_temp_diff < 0 ? ave_temp_diff=-ave_temp_diff : ""
  if ave_temp_diff < min_ave_temp
    min_ave_temp = ave_temp_diff
    min_ave_num = i+1
  end
end

puts min_ave_num