#!/usr/bin/env ruby
# by Jeffrey Matthias

def get_optimal_value(capacity, weights, values)
  value = 0.0
  # your code here
  value
end

if __FILE__ == $0
  number_of_items, capacity = gets.split().map(&:to_i)
  values = []
  weights = []
  number_of_items.times do
  	value, weight = gets.split().map(&:to_i)
  	values << value
  	weights << weight
  end

  answer = get_optimal_value(capacity, weights, values)
  puts "#{'%.4f' % answer}"
end