sum=596873;
nums = open('input.txt').map { |line| line.to_i }.sort_by {|i| (i < sum/2) ? sum - i : i};

i = 0;
while i < nums.length - 1  do
  if nums[i] + nums[i+1] == sum
    p "yes";
    exit 0;
  end
  i += 1;
end

p "no"