Problem: Everybody knows that the capital of Berland is connected to Bercouver (the Olympic capital) by a direct road. To improve the road's traffic capacity, there was placed just one traffic sign, limiting the maximum speed. Traffic signs in Berland are a bit peculiar, because they limit the speed only at that point on the road where they are placed. Right after passing the sign it is allowed to drive at any speed.

It is known that the car of an average Berland citizen has the acceleration (deceleration) speed of a km/h2, and has maximum speed of v km/h. The road has the length of l km, and the speed sign, limiting the speed to w km/h, is placed d km (1 ≤ d < l) away from the capital of Berland. The car has a zero speed at the beginning of the journey. Find the minimum time that an average Berland citizen will need to get from the capital to Bercouver, if he drives at the optimal speed.

The car can enter Bercouver at any speed.

Input

The first line of the input file contains two integer numbers a and v (1 ≤ a, v ≤ 10000). The second line contains three integer numbers l, d and w (2 ≤ l ≤ 10000; 1 ≤ d < l; 1 ≤ w ≤ 10000).

Output

Print the answer with at least five digits after the decimal point.

Examples

Input

1 1
2 1 3


Output

2.500000000000


Input

5 70
200 170 40


Output

8.965874696353

Solution (in JAVA):

Solution:
import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.HashSet;
import java.util.InputMismatchException;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.Map.Entry;
import java.util.PriorityQueue;
import java.util.Queue;
import java.util.Random;
import java.util.Set;
import java.util.SortedSet;
import java.util.Stack;
import java.util.TreeMap;
import java.util.TreeSet;

public class Main
{	
	/********************************************** a list of common variables **********************************************/
	private MyScanner scan = new MyScanner();
	private PrintWriter out = new PrintWriter(System.out);
	private final double PI = Math.PI;
	private final int INF = (int)(1e9);
	private final double EPS = 1e-6;
	private final int SIZEN = (int)(1e5);
	private final int MOD = (int)(1e9 + 7);
	private final long MODH = 10000000007L, BASE = 10007;
	private final int[] DX = {0, 1, 0, -1}, DY = {-1, 0, 1, 0};

  	public void foo()
  	{
  		double a = scan.nextInt();
  		double v = scan.nextInt();
  		double len = scan.nextInt();
  		double d = scan.nextInt();
  		double w = scan.nextInt();
  		double ans = 0, d1 = 0, d2 = 0, vx = 0;
  		if(w <= v)
  		{
  			d1 = (2 * v * v - w * w) / (2 * a);
  			d2 = w * w / (2 * a);
  			vx = w;
  			if(d >= d1) ans = (2 * v - w) / a + (d - d1) / v;
  			else if(d >= d2) 
  			{
  				double v0 = Math.sqrt((2 * a * d + w * w) / 2);
  				ans = (2 * v0 - w) / a;
  			}
  			else 
			{
  				ans = Math.sqrt(2 * d / a);
  				vx = Math.sqrt(2 * a * d);
			}
  		}
  		else
  		{
  			d1 = v * v / (2 * a);
  			vx = v;
  			if(d >= d1) ans = v / a + (d - d1) / v;
  			else
  			{
  				vx = Math.sqrt((2 * a * d));
  				ans = Math.sqrt(2 * d / a);
  			}
  		}
  		d1 = (v * v - vx * vx) / (2 * a);
		if(len - d >= d1) ans += (v - vx) / a + (len - d - d1) / v;
		else
		{
			double v0 = Math.sqrt(2 * a * (len - d) + vx * vx);
			ans += (v0 - vx) / a;
		}
		out.println(ans);
  	}  

	public static void main(String[] args)
	{
		Main m = new Main();
		m.foo();
		m.out.close();
	}
	
	/********************************************** a list of common algorithms **********************************************/
	/**
	 * 1---Get greatest common divisor
	 * @param a :	first number
	 * @param b :	second number
	 * @return		greatest common divisor
	 */
	public long gcd(long a, long b)
	{
		return 0 == b ? a : gcd(b, a % b);
	}
	
	/**
	 * 2---Get the distance from a point to a line
	 * @param x1	the x coordinate of one endpoint of the line
	 * @param y1	the y coordinate of one endpoint of the line
	 * @param x2	the x coordinate of the other endpoint of the line
	 * @param y2	the y coordinate of the other endpoint of the line
	 * @param x		the x coordinate of the point 
	 * @param y		the x coordinate of the point
	 * @return		the distance from a point to a line
	 */
	public double getDist(long x1, long y1, long x2, long y2, long x, long y)
	{
		long a = y2 - y1;
		long b = x1 - x2;
		long c = y1 * (x2 - x1) - x1 * (y2 - y1);
		return Math.abs(a * x + b * y + c) / Math.sqrt(a * a + b * b);
	}
	
	/**
	 * 3---Get the distance from one point to a segment (not a line)
	 * @param x1	the x coordinate of one endpoint of the segment
	 * @param y1	the y coordinate of one endpoint of the segment
	 * @param x2	the x coordinate of the other endpoint of the segment
	 * @param y2	the y coordinate of the other endpoint of the segment
	 * @param x		the x coordinate of the point
	 * @param y		the y coordinate of the point
	 * @return		the distance from one point to a segment (not a line)
	 */
	public double ptToSeg(long x1, long y1, long x2, long y2, long x, long y)
	{
		double cross = (x2 - x1) * (x - x1) + (y2 - y1) * (y - y1);
		if(cross <= 0)
		{
			return (x - x1) * (x - x1) + (y - y1) * (y - y1);
		}
		double d = (x2 - x1) * (x2 - x1) + (y2 - y1) * (y2 - y1);
		if(cross >= d) 
		{
			return (x - x2) * (x - x2) + (y - y2) * (y - y2);
		}
		double r = cross / d;
		double px = x1 + (x2 - x1) * r;
		double py = y1 + (y2 - y1) * r;
		return (x - px) * (x - px) + (y - py) * (y - py);
	}
	
	/**
	 * 4---KMP match, i.e. kmpMatch("abcd", "bcd") = 1, kmpMatch("abcd", "bfcd") = -1.
	 * @param t:	String to match.
	 * @param p:	String to be matched.
	 * @return		if can match, first index; otherwise -1.
	 */
	public int kmpMatch(char[] t, char[] p)
	{
		int n = t.length;
		int m = p.length;
		int[] next = new int[m + 1];
		next[0] = -1;
		int j = -1;
		for(int i = 1;i < m;++i)
		{
			while(j >= 0 && p[i] != p[j + 1])
			{
				j = next[j];
			}
			if(p[i] == p[j + 1])
			{
				++j;
			}
			next[i] = j;
		}
		j = -1;
		for(int i = 0;i < n;++i)
		{
			while(j >= 0 && t[i] != p[j + 1])
			{
				j = next[j];
			}
			if(t[i] == p[j + 1])
			{
				++j;
			}
			if(j == m - 1)
			{
				return i - m + 1;
			}
		}
		return -1;
	}
	
	/**
	 * 5---Get the hash code of a String
	 * @param	s:	input string
	 * @return	hash code
	 */
	public long hash(String s)
	{
		long key = 0, t = 1;
		for(int i = 0;i < s.length();++i)
		{
			key = (key + s.charAt(i) * t) % MODH;
			t = t * BASE % MODH;
		}
		return key;
	}
	
	/**
	 * 6---Get x ^ n % MOD quickly.
	 * @param	x:	base
	 * @param 	n:	times
	 * @return	x ^ n % MOD
	 */
	public long quickMod(long x, long n)
	{
		long ans = 1;
		while(n > 0)
		{
			if(1 == n % 2)
			{
				ans = ans * x % MOD;
 			}
			x = x * x % MOD;
			n >>= 1;
		}
		return ans;
	}
	
	/**
	 * 7---judge if a point is located inside a polygon
	 * @param x0	the x coordinate of the point
	 * @param y0	the y coordinate of the point
	 * @return true if it is inside the polygon, otherwise false
	 */
	/*public boolean contains(double x0, double y0)
	{
		int cross = 0;
		for(int i = 0;i < n;++i)
		{
			double s = x[i + 1] == x[i] ? 100000000 : (double)(y[i + 1] - y[i]) / (x[i + 1] - x[i]);
			boolean b1 = x[i] <= x0 && x0 < x[i + 1];
			boolean b2 = x[i + 1] <= x0 && x0 < x[i];
			boolean b3 = y0 < s * (x0 - x[i]) + y[i];
			if((b1 || b2) && b3) ++cross;
		}
		return cross % 2 != 0;
	}*/
	
	/**
	 * 8---judge if a point is located on the segment
	 * @param	x1	the x coordinate of one point of the segment
	 * @param	y1	the y coordinate of one point of the segment
	 * @param 	x2	the x coordinate of another point of the segment
	 * @param 	y2	the y coordinate of another point of the segment
	 * @param	x	the x coordinate of the point
	 * @param 	y	the y coordinate of the point
	 * @return	true if it is located on the segment, otherwise false
	 */
	public boolean isOnSeg(long x1, long y1, long x2, long y2, long x, long y)
	{
		return (x - x1) * (y2 - y1) == (x2 - x1) * (y - y1) && 
				x >= Math.min(x1, x2) && x <= Math.max(x1, x2) && 
				y >= Math.min(y1, y2) && y <= Math.max(y1, y2);
	}
	
	/**
	 * 9---get the cross product
	 * @param 	p1	point A
	 * @param 	p2	point B
	 * @param 	p	point O
	 * @return	cross product of OA x OB
	 */
	/*public long cross(Point p1, Point p2, Point p)
	{
		return (long)(p1.x - p.x) * (p2.y - p.y) - (long)(p2.x - p.x) * (p1.y - p.y);
	}*/
	
	/**
	 * 10---implement topsort and tell if it is possible
	 * @return true if it is possible to implement topsort, otherwise false
	 */
	/*public boolean topsort()
	{
		Queue<Integer> q = new LinkedList<Integer>();
		StringBuilder ans = new StringBuilder();
		int[] in = new int[26];
		for(int i = 0;i < 26;++i)
		{
			if(0 == in[i]) 
			{
				ans.append((char)('a' + i));
				q.add(i);
			}
		}
		while(!q.isEmpty())
		{
			int u = q.poll();
			for(int i = 0;i < 26;++i)
			{
				if(map[u][i])
				{
					--in[i];
					if(0 == in[i])
					{
						ans.append((char)('a' + i));
						q.add(i);
					}
				}
			}
		}
		return 26 == ans.length();
	}*/
	
	class MyScanner
	{
	    private byte[] buf = new byte[1024];
	    private int curChar;
	    private int numChars;
	    BufferedInputStream bis = new BufferedInputStream(System.in);

	    public int read() 
	    {
	        if (-1 == numChars)
	        {
	        	throw new InputMismatchException();
	        }
	        if (curChar >= numChars)
	        {
	            curChar = 0;
	            try 
	            {
	                numChars = bis.read(buf);
	            }
	            catch (IOException e)
	            {
	                throw new InputMismatchException();
	            }
	            if (numChars <= 0)
	            {
	            	return -1;
	            }
	        }
	        return buf[curChar++];
	    }

	    public int nextInt() 
	    {
	        int c = read();
	        while (isSpaceChar(c))
	        {
	        	c = read();
	        }
	        int sgn = 1;
	        if (c == '-') 
	        {
	            sgn = -1;
	            c = read();
	        }
	        int res = 0;
	        do 
	        {
	            if (c < '0' || c > '9')
	            {
	            	throw new InputMismatchException();
	            }
	            res *= 10;
	            res += c - '0';
	            c = read();
	        } while (!isSpaceChar(c));
	        return res * sgn;
	    }
	    
	    public long nextLong() 
	    {
	    	int c = read();
	    	while (isSpaceChar(c))
	    	{
	    		c = read();
	    	}
	    	int sgn = 1;
	    	if (c == '-') 
	    	{
	    		sgn = -1;
	    		c = read();
	    	}
	    	long res = 0;
	    	do 
	    	{
	    		if (c < '0' || c > '9')
	    		{
	    			throw new InputMismatchException();
	    		}
	    		res *= 10;
	    		res += c - '0';
	    		c = read();
	    	} while (!isSpaceChar(c));
	    	return res * sgn;
	    }
	    
	    public double nextDouble() 
	    {
	        int c = read();
	        while (isSpaceChar(c))
	        {
	        	c = read();
	        }
	        int sgn = 1;
	        if (c == '-')
	        {
	            sgn = -1;
	            c = read();
	        }
	        double res = 0;
	        while (!isSpaceChar(c) && c != '.') 
	        {
	            if (c == 'e' || c == 'E')
	            {
	            	return res * Math.pow(10, nextInt());
	            }
	            if (c < '0' || c > '9')
	            {
	            	throw new InputMismatchException();
	            }
	            res *= 10;
	            res += c & 15;
	            c = read();
	        }
	        if (c == '.') 
	        {
	            c = read();
	            double m = 1;
	            while (!isSpaceChar(c)) 
	            {
	                if (c == 'e' || c == 'E')
	                {
	                	return res * Math.pow(10, nextInt());
	                }
	                if (c < '0' || c > '9')
	                {
	                	throw new InputMismatchException();
	                }
	                m /= 10;
	                res += (c & 15) * m;
	                c = read();
	            }
	        }
	        return res * sgn;
	    }
	    
	    public String next()
	    {
	        int c = read();
	        while (isSpaceChar(c))
	        {
	        	c = read();
	        }
	        StringBuilder res = new StringBuilder();
	        do 
	        {
	            res.appendCodePoint(c);
	            c = read();
	        } while (!isSpaceChar(c));
	        return res.toString();
	    }

	    private boolean isSpaceChar(int c) 
	    {
	        return ' ' == c || '\n' == c || '\r' == c || '\t' == c || -1 == c;
	    }
	}
}