Chemical Experiment

In chemistry, a solution has a different meaning from a solution in computer programming.

If x liters of a substance are mixed with (100 - x) liters of water, the result is 100 liters of an x% solution of that substance.

Dasom has N bottles containing solutions of the same substance. Each bottle has a label showing how much solution it contains and what its concentration is.

Dasom wants to choose any amounts from these bottles and combine them into one bottle to make a solution whose concentration is exactly M%. A whole bottle does not have to be used; any partial amount may be taken and mixed.

Find the maximum number of liters of M% solution that can be made.

The first line contains the number of bottles N and the target concentration M.

N is a positive integer not greater than 50, and M is a nonnegative integer not greater than 100.

Each of the next N lines contains the information for one bottle. Each line gives the concentration written on the label and the amount of solution in the bottle, separated by a space. The concentration is a nonnegative integer not greater than 100, and the amount of solution is a positive integer not greater than 1000.

Print the maximum amount, in liters, of M% solution that can be made.

An absolute or relative error of at most 10^-2 is accepted.

A solution below the target concentration contributes a deficit of substance, while a solution above the target concentration contributes an excess. The mixture reaches the target concentration exactly when the total deficit and total excess are balanced.