/* package whatever; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;
import java.util.regex.Pattern;

/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	private static final Pattern ALL_NON_NUMERICS_EXCEPT_LEADING_MINUS_AND_E_AND_LAST_DOT_OR_COMMA = Pattern.compile("[^\\d,.\\-+eE]|(?<!(^|[eE]))\\s*[+\\-]|[eE](?!\\s*[+\\-]?\\s*\\d+$)|[.,](?=.*[.,])");

	public static void main (String[] args) throws java.lang.Exception
	{
		var intermediate = ALL_NON_NUMERICS_EXCEPT_LEADING_MINUS_AND_E_AND_LAST_DOT_OR_COMMA
            .matcher("3 e   -9")
            .replaceAll("");
            
        System.out.println(intermediate);
	}
}