N = STDIN.gets.chomp.to_i
T, A = STDIN.gets.chomp.split(" ").map(&:to_i)
Hs = STDIN.gets.chomp.split(" ").map(&:to_i)

puts (1..N).zip(Hs).map{|index, h| [index, T - h * 0.006]}.map{|index, t| [index, (A - t).abs]}.min{|a, b| a[1] <=> b[1]}.first

