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.*;
import java.util.*;
public class code {
	static PrintWriter pw;
	static boolean[] visit;
	static ArrayList<Pair>[] adj;
	static ArrayList<Integer> list;
	static long max=01;
	static void dfs(int i, long c) {
		visit[i]=true;
		max=Math.max(c, max);
		for(Pair p: adj[i]) {
			if(!visit[p.x-1]) {
				dfs(p.x-1, c+1l*p.y);
			}
		}
	}
	static int sign(long x) {
		return x>0?1:-1;
	}
	public static long gcf(long x, long y) {
		while(x%y!=0 && y%x!=0) {
			if(x>y)
				x%=y;
			else
				y%=x;
		}
		return x>y? y:x;
	}
	static long lcm(long a, long b) {
		return (a*b)/gcf(a,b);
	}
	public static void main(String[] args) throws Exception {
		Scanner sc= new Scanner(System.in);
		pw = new PrintWriter(System.out);
		double h=sc.nextLong(),l=sc.nextLong();
		pw.println((l*l-h*h)/(2*h));
		pw.close();
	}
	static class Scanner {
		StringTokenizer st;
		BufferedReader br;
 
		public Scanner(InputStream s) {
			br = new BufferedReader(new InputStreamReader(s));
		}
 
		public Scanner(FileReader r) {
			br = new BufferedReader(r);
		}
 
		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 double nextDouble() throws IOException {
			return Double.parseDouble(next());
		}
 
		public int[] nextArr(int n) throws IOException {
			int[] arr = new int[n];
			for (int i = 0; i < arr.length; i++)
				arr[i] = nextInt();
			return arr;
		}
		public Integer[] nextsort(int n) throws IOException{
			Integer[] arr=new Integer[n];
			for(int i=0; i<n; i++) 
				arr[i]=nextInt();
			return arr;
		}
		public boolean ready() throws IOException {
			return br.ready();
		}
	}
	static class Pair implements Comparable<Pair>{
		int x;
		int y;
		public Pair(int a, int b) {
			this.x=a;
			this.y=b;
		}
		public int compareTo(Pair other) {
			return this.y-other.y;
		}
	}
	static class Triple implements Comparable<Triple>{
		int x;
		int y;
		boolean d;
		public Triple(int a, int b, boolean t) {
			this.x=a;
			this.y=b;
			this.d=t;
		}
		public int compareTo(Triple other) {
			if(this.d && !other.d) {
				return 1;
			}else if(!this.d && other.d) {
				return -1;
			}else {
				return this.y-other.y;
			}
		}
	}
}