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.

<image>

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
import java.io.BufferedReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.StringTokenizer;
import java.util.TreeSet;

import javax.swing.plaf.synth.SynthSeparatorUI;
public class Problem1 {
	private static final long INF = (long) 1E15;
	static Scanner sc=new Scanner(System.in);
	static PrintWriter out=new PrintWriter(System.out);
	
	static final int upperBound = (int)10000002;

	static ArrayList<Integer>[] modifiedSieve(int N)
	{
		ArrayList<Integer>[] pf = new ArrayList[N];
		for(int i = 1; i < N; ++i)
			pf[i] = new ArrayList<Integer>();
		for(int i = 2; i < N; ++i)
			if(pf[i].isEmpty())
				for(int j = i<<1; j < N; j += i)
					pf[j].add(i);
		return pf;
	}
	
	static int pow(long a, int n)
	{
		int res = 1;
		while(n != 0)
		{
			if((n & 1) == 1)
				res *= a;
			a *= a;
			n >>= 1;			
		}
		return res;
	}
	static HashSet<Long> primeFactors(long N)		// O(sqrt(N) / ln sqrt(N))
	{
		HashSet<Long> factors = new HashSet
				<Long>();		//take abs(N) in case of -ve integers
		int idx = 0;
				long p = primes.get(idx);

		while(p * p <= N)
		{if(idx+1==primes.size()) {
		break;	
		}
			while(N % p == 0) { factors.add(p); N /= p; }
			
			p = primes.get(++idx);
		}

		if(N != 1)						// last prime factor may be > sqrt(N)
			factors.add(N);				// for integers whose largest prime factor has a power of 1
		return factors;
	}
static int[] pf;
	
	static void pf(int N)
	{
		pf = new int[N];
		for(int i = 2; i < N; ++i)
			if(pf[i] == 0)
			{
				for(int j = i; j < N; j += i)
				{
					int p = 0, k = j;
					while(k % i == 0)
					{
						k /= i;
						++p;
					}
					pf[j] += p;
				}
			}
	}
	public static void main(String[] args) throws IOException {
		double h=sc.nextDouble();
		double l=sc.nextDouble();
		double theta1=Math.atan(l/h);
		double theta2=Math.atan(h/l);
		theta1=Math.toDegrees(theta1);
		theta2=Math.toDegrees(theta2);
		double theta3=theta1-theta2;
		System.out.println(Math.tan(Math.toRadians(theta3))*l);
		
	}	
	static int m=(int) (1e9+7);
	
	    		static ArrayList<Integer> primes;
		static boolean[] isComposite;

		static void sieve(int N)	// O(N log log N) 
		{
			isComposite = new boolean[N+1];	
			Arrays.fill(isComposite, true);
			isComposite[0] = isComposite[1] = false;			// 0 indicates a prime number
			primes = new ArrayList<Integer>();

			for (int i = 2; i <= N; ++i) 					//can loop till i*i <= N if primes array is not needed O(N log log sqrt(N)) 
				if (isComposite[i] == true) 					//can loop in 2 and odd integers for slightly better performance
				{
					primes.add(i);
					if(1l * i * i <= N)
						for (int j = i * i; j <= N; j += i)	// j = i * 2 will not affect performance too much, may alter in modified sieve
							isComposite[j] = false;
				}   
		}
	
	
	static class Pair{
    	int val;
    	int count;
     Pair(int v,int c) {
    		val=v;
    		count=c;
    	}
    }

	
	
	static class Scanner 
	{
		StringTokenizer st;
		BufferedReader br;

		public Scanner(InputStream s){	br = new BufferedReader(new InputStreamReader(s));}

		public double nextDouble() throws NumberFormatException, IOException {
return Double.parseDouble(next());
		}

		public String next() throws IOException 
		{
			while (st == null || !st.hasMoreTokens()) 
				st = new StringTokenizer(br.readLine());
			return st.nextToken();
		}

		public int nextInt() throws IOException {return Integer.parseInt(next());}
		
		public long nextLong() throws IOException {return Long.parseLong(next());}

		public String nextLine() throws IOException {return br.readLine();}

		public boolean ready() throws IOException {return br.ready();}

		public void waitForInput() throws InterruptedException {Thread.sleep(1000);}
	}
}