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

class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		String input = "I have 100 friends and 1 evil";
		System.out.println(input.replaceFirst(".*?(\\d{3}).*", "$1"));
		System.out.println(input.replaceFirst(".*?(?<!\\d)(\\d{3})(?!\\d).*", "$1"));
		System.out.println(input.replaceFirst(".*?\\b(\\d{3})\\b.*", "$1"));
		System.out.println(input.replaceFirst(".*?(?<!\\S)(\\d{3})(?!\\S).*", "$1"));
	}
}