gistfile1.txt

import java.io.*;
import java.util.Scanner;

public class DNA2
{
  public static void main(String[] args) throws IOException
	{
		File inFile = new File("C:/CS312/dna.txt");
		Scanner sc = new Scanner(inFile);
		String line = sc.nextLine();
		int n = Integer.parseInt(line);
		for(int i = 0; i < n; i++)
		{
			String line1 = sc.nextLine();
			String line2 = sc.nextLine();
			String dna1, dna2;
			if(line1.length() > line2.length())
			{
				dna1 = line1;
				dna2 = line2;
			}
			else
			{
				dna1 = line2;
				dna2 = line1;
			}
			System.out.println(common(dna1 , dna2));
		}
		sc.close();
	}

	public static String common(String dna1, String dna2)
	{
		String temp = " ";
		String longest = " ";
		int found;
		for (int start = 0; start < dna2.length();start++)
		{
			for (int end = 1; end < (dna2.length() - 1); end++)
			{
				temp = dna2.substring(start, end);
				found = dna1.indexOf(temp);
				if (found != -1)
				{
					longest=temp;
				}
			}
		}
		return longest;
	}
}