Problem: A very unusual citizen lives in a far away kingdom — Dwarf Gracula. However, his unusual name is not the weirdest thing (besides, everyone long ago got used to calling him simply Dwarf Greg). What is special about Dwarf Greg — he's been living for over 200 years; besides, he lives in a crypt on an abandoned cemetery and nobody has ever seen him out in daytime. Moreover, nobody has ever seen Greg buy himself any food. That's why nobody got particularly surprised when after the infernal dragon's tragic death cattle continued to disappear from fields. The people in the neighborhood were long sure that the harmless dragon was never responsible for disappearing cattle (considering that the dragon used to be sincere about his vegetarian views). But even that's not the worst part of the whole story.

The worst part is that merely several minutes ago Dwarf Greg in some unintelligible way got inside your house and asked you to help him solve a problem. The point is that a short time ago Greg decided to order a new coffin (knowing his peculiar character, you are not surprised at all). But the problem is: a very long in both directions L-shaped corridor leads to Greg's crypt, and you can't drag just any coffin through that corridor. That's why he asked you to help.

<image>

You've formalized the task on a plane like this: let the corridor's width before and after the turn be equal to a and b correspondingly (see the picture). The corridor turns directly at a right angle, the coffin is a rectangle whose length and width are equal to l and w (l ≥ w) correspondingly. Dwarf Greg has already determined the coffin's length (l), which is based on his height; your task is to determine the coffin's maximally possible width (w), at which it can be brought to the crypt. Besides, due to its large mass (pure marble!) the coffin is equipped with rotating wheels; therefore it is impossible to lift it off the ground, however, arbitrary moves and rotations of the coffin in the plane become possible. The coffin may be rotated arbitrarily just before you drag it into crypt and move through the corridor.

Greg promised that if you help him, he will grant you immortality (I wonder how?). And if you don't, well... trust me, you don't want to know what happens if you don't help him...

Input

The first line contains three space-separated integers a, b and l from the problem's statement (1 ≤ a, b, l ≤ 104).

Output

Print the maximally possible width of a coffin with absolute or relative error no more than 10 - 7. If a coffin with the given length and positive width (the coffin that would meet the conditions from the problem's statement) does not exist, print "My poor head =(" (without quotes).

It is guaranteed that if the answer is positive, it will be not less than 10 - 7. All the hacks will also be checked to meet that condition.

Examples

Input

2 2 1


Output

1.0000000


Input

2 2 2


Output

2.0000000

Input

2 2 3


Output

1.3284271


Input

2 2 6


Output

My poor head =(

Note

In the first example the answer is restricted by the coffin's length (remember — coffin's widths should not be larger than it's length).

In the second example it is possible to drag the coffin through the corridor thanks to rotating wheels: firstly, drag it forward by one side while it will not be hampered by the wall, then move it forward by adjacent side perpendicularly to the initial movement direction (remember — arbitrary moves and rotations of the coffin are possible).

Solution (in JAVA):

Solution:


import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintStream;

/**
 * @author Ivan Pryvalov (ivan.pryvalov@gmail.com)
 */
public class Codeforces78_Div2_ProblemE implements Runnable{

	double A,B,L;
	double EPS = 1e-10;
	
	private void solve() throws IOException {
		A = scanner.nextInt();
		B = scanner.nextInt();
		L = scanner.nextInt();

		double w = 0;
		if (B-L > -EPS || A-L > -EPS){
			w = Math.min(L, Math.min(A, B));
			out.println(w);
			return;
		}
		
		if (!check(w)){
			out.println("My poor head =(");
		}else{
			double w2 = 1e-8;
			while (check(w2)){
				w2 *= 2;
			}
			double w1 = w2/2.0;
			w = binarySearch(w1,w2);
			out.println(w);
		}
	}

	private double binarySearch(double w1, double w2) {
		while (Math.abs(w2-w1)>EPS){
			double w = (w1+w2)/2.0;
			if (check(w)){
				w1 = w;
			}else{
				w2 = w;
			}
		}
		return (w1+w2)/2.0;
	}

	private boolean check(double w) {
		double minL = binarySearchMinL(w, 0, Math.PI/2);
		return minL - L > -EPS && L-w > -EPS; 
	}

	private double binarySearchMinL(double w, double l, double r) {
		while (Math.abs(l-r)>EPS){
			double c = (l+r)/2.0;
			double dc = 1e-8;
			double fC = getL(c,w);
			double fC2 = getL(c+dc,w);
			if (fC2 > fC){
				r = c;
			}else{
				l = c;
			}
		}
		return getL(l, w);
	}

	public double getL(double a, double w){
		return A/Math.cos(a) + B/Math.sin(a) - 2*w/Math.sin(2*a);
	}

	/////////////////////////////////////////////////
	final int BUF_SIZE = 1024 * 1024 * 8;//important to read long-string tokens properly
	final int INPUT_BUFFER_SIZE = 1024 * 1024 * 8 ;
	final int BUF_SIZE_INPUT = 1024;
	
	final int BUF_SIZE_OUT = 1024;
	
	boolean inputFromFile = false;
	String filenamePrefix = "A-small-attempt0";
	String inSuffix = ".in";
	String outSuffix = ".out";
	
	//InputStream bis;
	//OutputStream bos;
	PrintStream out;
	ByteScanner scanner;
	ByteWriter writer;
	
	@Override
	public void run() {
		try{
			InputStream bis = null;
			OutputStream bos = null;
			//PrintStream out = null;
			if (inputFromFile){
				File baseFile = new File(getClass().getResource("/").getFile());
				bis = new BufferedInputStream(
						new FileInputStream(new File(
								baseFile, filenamePrefix+inSuffix)),
								INPUT_BUFFER_SIZE);
				bos = new BufferedOutputStream(
						new FileOutputStream(
								new File(baseFile, filenamePrefix+outSuffix)));
				out = new PrintStream(bos);
			}else{
				bis = new BufferedInputStream(System.in, INPUT_BUFFER_SIZE);
				bos = new BufferedOutputStream(System.out);
				out = new PrintStream(bos);
			}
			scanner = new ByteScanner(bis, BUF_SIZE_INPUT, BUF_SIZE);
			writer = new ByteWriter(bos, BUF_SIZE_OUT);
			
			solve();
			out.flush();
		}catch (Exception e) {
			e.printStackTrace();
			System.exit(1);
		}
	}
	
	public interface Constants{
		final static byte ZERO = '0';//48 or 0x30
		final static byte NINE = '9';
		final static byte SPACEBAR = ' '; //32 or 0x20
		final static byte MINUS = '-'; //45 or 0x2d	
		
		final static char FLOAT_POINT = '.';
	}
	
	public static class EofException extends IOException{
	}
	
	public static class ByteWriter implements Constants {
		
		int bufSize = -1;//1024;
		byte[] byteBuf = null;//new byte[bufSize];
		OutputStream os;
		
		public ByteWriter(OutputStream os, int bufSize){
			this.os = os;
			this.bufSize = bufSize;
			byteBuf = new byte[bufSize];
		}
		
		public void writeInt(int num) throws IOException{
	         int byteWriteOffset = byteBuf.length;
	         if (num==0){
	        	 byteBuf[--byteWriteOffset] = ZERO;
	         }else{
	        	 int numAbs = Math.abs(num);
	        	 while (numAbs>0){
	        		 byteBuf[--byteWriteOffset] = (byte)((numAbs % 10) + ZERO);
	        		 numAbs /= 10;
	        	 }
	        	 if (num<0) byteBuf[--byteWriteOffset] = MINUS;
	         }
	         os.write(byteBuf, byteWriteOffset, byteBuf.length - byteWriteOffset);
		}
		
		public void writeLong(long num) throws IOException{
	         int byteWriteOffset = byteBuf.length;
	         if (num==0){
	        	 byteBuf[--byteWriteOffset] = ZERO;
	         }else{
	        	 long numAbs = Math.abs(num);
	        	 while (numAbs>0){
	        		 byteBuf[--byteWriteOffset] = (byte)((numAbs % 10) + ZERO);
	        		 numAbs /= 10;
	        	 }
	        	 if (num<0) byteBuf[--byteWriteOffset] = MINUS;
	         }
	         os.write(byteBuf, byteWriteOffset, byteBuf.length - byteWriteOffset);
		}
		
		/* No need
		public void writeDouble(double num) throws IOException{
			byte[] data = Double.toString(num).getBytes();
			os.write(data,0,data.length);
		}*/
		
		//NO NEED: Please ensure ar.length <= byteBuf.length!
		/**
		 * 
		 * @param ar
		 * @throws IOException
		 */
		public void writeByteAr(byte[] ar) throws IOException{
			/*
			for (int i = 0; i < ar.length; i++) {
				byteBuf[i] = ar[i];
			}
			os.write(byteBuf,0,ar.length);*/
			os.write(ar,0,ar.length);
		}
		
		public void writeSpaceBar() throws IOException{
			os.write(SPACEBAR);
		}
		
	}
	
	public static class ByteScanner implements Constants{
		
		InputStream is;
		
		public ByteScanner(InputStream is, int bufSizeInput, int bufSize){
			this.is = is;
			this.bufSizeInput = bufSizeInput;
			this.bufSize = bufSize;
			
			byteBufInput = new byte[this.bufSizeInput];
			byteBuf = new byte[this.bufSize];
		}
		
		public ByteScanner(byte[] data){
			byteBufInput = data;
			bufSizeInput = data.length;
			bufSize = data.length;
			byteBuf = new byte[bufSize];
			byteRead = data.length;
			bytePos = 0;
		}
		
		private int bufSizeInput;
		private int bufSize;
		
		byte[] byteBufInput;
		byte by=-1;
		int byteRead=-1;
		int bytePos=-1;

		static byte[] byteBuf;
		int totalBytes;
		
		boolean eofMet = false;
		
		private byte nextByte() throws IOException{
			
			if (bytePos<0 || bytePos>=byteRead){
				byteRead = is==null? -1: is.read(byteBufInput);
				bytePos=0;
				if (byteRead<0){
					byteBufInput[bytePos]=-1;//!!!
					if (eofMet)
						throw new EofException();
					eofMet = true;
				}
			}
			return byteBufInput[bytePos++];
		}
		
		/**
		 * Returns next meaningful character as a byte.<br>
		 * 
		 * @return
		 * @throws IOException
		 */
		public byte nextChar() throws IOException{
			while ((by=nextByte())<=0x20);
			return by;
		}
		
		/**
		 * Returns next meaningful character OR space as a byte.<br>
		 * 
		 * @return
		 * @throws IOException
		 */
		public byte nextCharOrSpacebar() throws IOException{
			while ((by=nextByte())<0x20);
			return by;
		}
		
	    /**
	     * Reads line.
	     * 
	     * @return
	     * @throws IOException
	     */
	    public String nextLine() throws IOException {
            readToken((byte)0x20);
            return new String(byteBuf,0,totalBytes);
	    }
	    
	    public byte[] nextLineAsArray() throws IOException {
            readToken((byte)0x20);
            byte[] out = new byte[totalBytes];
            System.arraycopy(byteBuf, 0, out, 0, totalBytes);
            return out;
	    }
	    
		
	    /**
	     * Reads token. Spacebar is separator char.
	     * 
	     * @return
	     * @throws IOException
	     */
	    public String nextToken() throws IOException {
            readToken((byte)0x21);
            return new String(byteBuf,0,totalBytes);
	    }
	    
	    /**
	     * Spacebar is included as separator char
	     * 
	     * @throws IOException
	     */
	    private void readToken() throws IOException {	    	
            readToken((byte)0x21);
	    }
	    
	    private void readToken(byte acceptFrom) throws IOException {
            totalBytes = 0;
            while ((by=nextByte())<acceptFrom);
            byteBuf[totalBytes++] = by;
            while ((by=nextByte())>=acceptFrom){
                byteBuf[totalBytes++] = by;
            }
	    }
		
	    public int nextInt() throws IOException{
			readToken();
			int num=0, i=0;
			boolean sign=false;
			if (byteBuf[i]==MINUS){
				sign = true;
				i++;
			}
			for (; i<totalBytes; i++){
				num*=10;
				num+=byteBuf[i]-ZERO;
			}
			return sign?-num:num;
		}
		
		public long nextLong() throws IOException{
			readToken();
			long num=0;
			int i=0;
			boolean sign=false;
			if (byteBuf[i]==MINUS){
				sign = true;
				i++;
			}
			for (; i<totalBytes; i++){
				num*=10;
				num+=byteBuf[i]-ZERO;
			}
			return sign?-num:num;
		}
		
		/*
		//TODO test Unix/Windows formats
		public void toNextLine() throws IOException{
			while ((ch=nextChar())!='\n');
		}
		*/
		
		public double nextDouble() throws IOException{
			readToken();
			char[] token = new char[totalBytes];
			for (int i = 0; i < totalBytes; i++) {
				token[i] = (char)byteBuf[i];
			}
			return Double.parseDouble(new String(token));
		}
	    
	}
	
	public static void main(String[] args) {
		new Codeforces78_Div2_ProblemE().run();
	}
	
}