problem 4

Tillage

Reduced tillage or conservation tillage is a practice of minimising soil disturbance and allowing crop residue or stubble to remain on the ground instead of being thrown away or incorporated into the soil. 30 % of the residue becomes natural manure.

Given the total weight of the residue and the total amount of manure needed for the next crop, write a program to determine the amount of manure needed extra. 

Input Format: 

The first line of the input is an integer that corresponds to the total weight of the residue. 
The second line of the input is an integer that corresponds to the total amount of manure needed. 

 

Output Format: 

An output is a float value that corresponds to the amount of manure needed extra, rounded off to 2 decimal places. 

Sample Input:

100

100

Sample Output:

70.00