a=gets.chomp.to_i
b=gets.split.map(&:to_i)
c=gets.split.map(&:to_i)

for i in 0..(b.length-1)
  c[i]=b[0]-(c[i]*0.006)
end

d=0
for i in 1..(b.length-1)      
   d=i if (b[1]-c[d]).abs > (b[1]-c[i]).abs
end

puts d