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
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.StringTokenizer;

import static java.lang.Math.*;

public class code1 {
    private static boolean oj = System.getProperty("ONLINE_JUDGE") != null;
    private static Reader in;
    private static PrintWriter out;
    ////////////////////////////////////////////////////////////////////////////////////////////////////
    private static int min(int... a){int min=a[0]; for(int i:a) min=Math.min(min, i); return min;}
    private static int max(int... a){int max=a[0]; for(int i:a) max=Math.max(max, i); return max;}
    private static long min(long... a){long min=a[0]; for(long i:a)min=Math.min(min, i); return min;}
    private static long max(long... a){long max=a[0]; for(long i:a)max=Math.max(max, i); return max;}
    private static String strm(String str, long m) {
        String ans="";
        while(m>0) {
            if(m%2==1) ans=ans.concat(str);
            str=str.concat(str); m>>=1;
        } return ans;
    }
    private static long mod(long a, long mod) {long res = a%mod; return res>=0 ? res : res+mod;}
    private static int mod(int a, int mod) {int res = a%mod; return res>=0 ? res : res+mod;}
    private static long modpow(long x, int n, int mod) {
        long res = 1;
        for (long p = x; n > 0; n >>= 1, p = mod((mod(p, mod)*mod(p, mod)),  mod)) {
            if ((n & 1) != 0) res = mod(mod(res, mod) * mod(p, mod), mod);
        }
        return res;
    }
    private static long gcd(long a, long b) {return b == 0 ? Math.abs(a) : gcd(b, a % b);}
    private static int gcd(int a, int b) {return b == 0 ? Math.abs(a) : gcd(b, a % b);}
    private static long gcd(long... a) {long gcd=a[0]; for(long x:a) gcd=gcd(gcd, x); return gcd;}
    private static int gcd(int... a) {int gcd=a[0]; for(int x:a) gcd=gcd(gcd, x); return gcd;}
    private static long lcm(long a, long b) {return Math.abs(a / gcd(a, b) * b);}
    private static boolean isEven(int num) {return ((num&1) == 0);}
    private static boolean isOdd(int num) {return !isEven(num);}
    private static boolean isEven(long num) {return ((num&1) == 0);}
    private static boolean isOdd(long num) {return !isEven(num);}
    private static class Pair {
        public int x, y;
        public Pair(int x, int y) {
            this.x = x;
            this.y = y;
        }
        @Override
        public boolean equals(Object obj) {
            if (obj == this) return true;
            if (!(obj instanceof Pair)) return false;
            Pair pair = (Pair)obj;
            return this.x == pair.x && this.y == pair.y;
        }
        @Override
        public String toString() {
            return ("(" + this.x + "," + this.y + ")");
        }
        @Override
        public int hashCode() {
            return (this.x+" "+this.y).hashCode();
        }
    }
    private static class Triplet {
        public int x, y, z;
        public Triplet(int x, int y, int z) {
            this.x = x;
            this.y = y;
            this.z = z;
        }
        @Override
        public boolean equals(Object obj) {
            if (obj == this) return true;
            if (!(obj instanceof Triplet)) return false;
            Triplet triplet = (Triplet)obj;
            return this.x == triplet.x && this.y == triplet.y && this.z == triplet.z;
        }
        @Override
        public String toString() {
            return ("(" + this.x + "," + this.y + "," + this.z + ")");
        }
        @Override
        public int hashCode() {
            return (this.x+" "+this.y+" "+this.z).hashCode();
        }
    }
    ////////////////////////////////////////////////////////////////////////////////////////////////////
    static class Reader {
        private BufferedReader br;
        private StringTokenizer token;
        private Reader(FileReader obj) {
            br = new BufferedReader(obj, 32768);
            token = null;
        }
        private Reader() {
            br = new BufferedReader(new InputStreamReader(System.in), 32768);
            token = null;
        }
        private String next() {
            while(token == null || !token.hasMoreTokens()) {
                try {
                    token = new StringTokenizer(br.readLine());
                } catch (Exception e) {e.printStackTrace();}
            } return token.nextToken();
        }
        private String nextLine() {
            String str="";
            try {
                str = br.readLine();
            } catch (Exception e) {e.printStackTrace();}
            return str;
        }
        private int nextInt() {return Integer.parseInt(next());}
        private long nextLong() {return Long.parseLong(next());}
        private double nextDouble() {return Double.parseDouble(next());}
        private long[] nextLongArr(int n) {
            long[] arr = new long[n]; for(int i=0; i<n; i++) arr[i] = nextLong(); return arr;
        }
        private int[] nextIntArr(int n) {
            int[] arr = new int[n]; for(int i=0; i<n; i++) arr[i] = nextInt(); return arr;
        }
    }
    ////////////////////////////////////////////////////////////////////////////////////////////////////
    private static final int mod = 1_000_000_007;

    
    private static void solve() throws Exception {
        double H = in.nextDouble(), L = in.nextDouble();
        out.printf("%f\n", L/tan(2*atan(H/L)));
    }
    private static void run() throws Exception {
        // in = new Reader();
        // in = new Reader(new FileReader("input.txt"));
        // out = new PrintWriter(new FileWriter("output.txt"));
        in = oj ? new Reader() : new Reader(new FileReader("/home/raiden/Desktop/input.txt"));
        out = new PrintWriter(System.out);
        // out = new PrintWriter(new FileWriter("/home/raiden/Desktop/output.txt"));
        long ti = System.currentTimeMillis();
        solve(); out.flush();
        if (!oj) System.out.println("\n"+(System.currentTimeMillis()-ti)+"ms");
    }
    public static void main(String[] args) throws Exception {run();}
}