Problem: While sailing on a boat, Inessa noticed a beautiful water lily flower above the lake's surface. She came closer and it turned out that the lily was exactly H centimeters above the water surface. Inessa grabbed the flower and sailed the distance of L centimeters. Exactly at this point the flower touched the water surface.

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Suppose that the lily grows at some point A on the lake bottom, and its stem is always a straight segment with one endpoint at point A. Also suppose that initially the flower was exactly above the point A, i.e. its stem was vertical. Can you determine the depth of the lake at point A?

Input

The only line contains two integers H and L (1 ≤ H < L ≤ 10^{6}).

Output

Print a single number — the depth of the lake at point A. The absolute or relative error should not exceed 10^{-6}.

Formally, let your answer be A, and the jury's answer be B. Your answer is accepted if and only if \frac{|A - B|}{max{(1, |B|)}} ≤ 10^{-6}.

Examples

Input


1 2


Output


1.5000000000000


Input


3 5


Output


2.6666666666667

Solution (in JAVA):

Solution:

import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.StringTokenizer;

public class bits {
    public static class FastReader {
			BufferedReader br;
			StringTokenizer st;
			//it reads the data about the specified point and divide the data about it ,it is quite fast
			//than using direct 
	 
			public FastReader() {
				br = new BufferedReader(new InputStreamReader(System.in));
			}
	 
			String next() {
				while (st == null || !st.hasMoreTokens()) {
					try {
						st = new StringTokenizer(br.readLine());
					} catch (Exception r) {
						r.printStackTrace();
					}
				}
				return st.nextToken();
			}
	 
			int nextInt() {
				return Integer.parseInt(next());//converts string to integer
			}
	 
			double nextDouble() {
				return Double.parseDouble(next());
			}
	 
			long nextLong() {
				return Long.parseLong(next());
			}
	 
			String nextLine() {
				String str = "";
				try {
					str = br.readLine();
				} catch (Exception r) {
					r.printStackTrace();
				}
				return str;
			}
		}
		
		public static PrintWriter out = new PrintWriter (new BufferedOutputStream(System.out));
	    
	static int ans=0;static int ar[]=new int[501];
static void bit(String a,String b)
{int ct=0;
	for(int i=0;i<a.length();i++)
	{
		if(a.charAt(i)=='1'||b.charAt(i)=='1')
			ct++;
	}
	ans=Math.max(ans, ct);
	ar[ct]++;
	
}
	public static void main(String[] args) {
		// TODO Auto-generated method stub
HashMap<Integer,Integer>map=new HashMap<Integer,Integer>();
ArrayList<Integer>list=new ArrayList<Integer>();
		FastReader in=new FastReader();
	
		double h=in.nextDouble();
		double l=in.nextDouble();
		double ans=(Math.pow(l, 2)-Math.pow(h, 2))/(2*h);
		System.out.println(ans);
		
	}

}