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.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.*;
public class Main {
    private static final FastReader scanner = new FastReader();
    public static void main(String[] args) {
        int h = scanner.nextInt();
        int l = scanner.nextInt();
        double ans =(double) l*l - (double) h*h ;
        ans/=h;
        ans/=2;
        System.out.println(ans);
    }
    private static String Sort(String s){
        char[] c  = s.toCharArray();
        Arrays.sort(c);
        return new String(c);
    }
    private static long ceildiv(long x,long y){
        return (x+y-1)/y;
    }
    private static void swap(int[] array , int a ,int b){
        if (a==b){
            return;
        }
        int temp = array[a];
        array[a] =array[b];
        array[b] =temp;
    }
    private static String revString(String str){
        StringBuilder sb = new StringBuilder(str);
        sb.reverse();
        return sb.toString();
    }
    private static int fibo(int n){
        int[] dp = new int[n];
        for(int i= 0 ;i<n;i++){
            if(i<2){
                dp[i] = 1;
            }else{
                dp[i] =dp[i-1]+dp[i-2];
            }
        }
        return dp[dp.length-1];
    }
    private static void swap(char[] array , int a,int b){
        if(a==b){
            return;
        }
        char temp = array[a];
        array[a] = array[b];
        array[b] = temp;
    }
    private static int max(int[] array ){
        int min = Integer.MIN_VALUE;
        for(int i = 0;i< array.length;i++){
            if(array[i]>min){
                min = array[i];
            }
        }
        return min;
    }
    private static int min(int[] array ){
        int min = Integer.MAX_VALUE;
        for(int i = 0;i< array.length;i++){
            if(array[i]<min){
                min = array[i];
            }
        }
        return min;
    }
    private static void readArray(int[] array){
        for(int i = 0;i< array.length;i++){
            array[i] = scanner.nextInt();
        }
    }
    private static int gcd(int a , int b){
        if(b==0) return  a;
        else return gcd(b,a%b);
    }
    private static long fact(int n){
        if(n==1 || n==0) return 1;
        else return (long) n*fact(n-1);
    }
    private static int Arraysum(int[] array){
        int sum = 0;
        for(int i = 0 ;i< array.length;i++){
            sum+=array[i];
        }
        return sum;
    }
    private static boolean isPrime(long n){
        if(n==1){
            return false;
        }
        for(long i = 2;i<=Math.sqrt(n);i++){
            if(n%i==0){
                return false;
            }
        }
        return true;
    }
    private static int multiply(int[] array){
        int mult = 1 ;
        for(int i = 0 ;i< array.length;i++) {
            mult *= array[i];
        }
        return mult;
    }
    private static int FromStringtoInt(String s){
        s = s.replaceAll("[^0-9]","");
        return Integer.parseInt(s);
    }
    static class BIT{
        static int[] BitTree = new int[1000];
        int sum(int index){
            int s =0;
//            index+=1;
            while (index>0){
                s+=BitTree[index];
                index-=(index&-index);
            }
            return s;
        }
        public static void updateBIT(int n, int index, int val) {
            index = index + 1;
            while(index <= n) {
                BitTree[index] += val;
                index += index & (-index);
            }
        }
        void constructBITree(int arr[], int n) {
            for(int i=1; i<=n; i++)
                BitTree[i] = 0;
            for(int i = 0; i < n; i++)
                updateBIT(n, i, arr[i]);
        }
    }
    static class FastReader {
        BufferedReader br;
        StringTokenizer st;

        public FastReader()
        {
            br = new BufferedReader(new
                    InputStreamReader(System.in));
        }

        String next()
        {
            while (st == null || !st.hasMoreElements())
            {
                try
                {
                    st = new StringTokenizer(br.readLine());
                }
                catch (IOException  e)
                {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        int nextInt()
        {
            return Integer.parseInt(next());
        }

        long nextLong()
        {
            return Long.parseLong(next());
        }

        double nextDouble()
        {
            return Double.parseDouble(next());
        }

        String nextLine()
        {
            String str = "";
            try
            {
                str = br.readLine();
            }
            catch (IOException e)
            {
                e.printStackTrace();
            }
            return str;
        }
    }
    private static int[] threeNumberSort(int[] array,int[] order){
        int f  = order[0];
        int s  = order[1];
        int t  = order[2];
        //
        int first = 0;
        int second = 0;
        int third = array.length-1;
        while(second<=third){
            int value = array[second];
            if(value == f){
                swap(array,first,second);
                first++;
                second++;
            }else if(value==t){
                swap(array,second,third);
                third--;
                // no action on second value
            }else if(value==s){
                second++;
            }
        }
        return array;
    }
}