import java.util.*;
import java.io.*;
public class Main{
public static String getMaxSubstr(String str1,String str2){
char[] arr1 = str1.toCharArray();
char[] arr2 = str2.toCharArray();
int len1 = arr1.length;
int len2 = arr2.length;
//The starting position of the longest substring
int start = 0;
//Length of the longest substring
int maxLen = 0;
//Add one more row and one column as auxiliary state
int[][] maxSubLen = new int[len1+1][len2+1];
for (int i = 1; i <= len1 ; i++) {
for (int j = 1; j < len2; j++) {
//If the i-th character and j-th character are equal, then the accumulation will be performed
if (arr1[i-1] == arr2[j-1]){
maxSubLen[i][j] = maxSubLen[i-1][j-1]+1;
if (maxLen < maxSubLen[i][j]){
maxLen = maxSubLen[i][j];
start = i - maxLen;
}
}
}
}
return str1.substring(start,start+maxLen);
}
public static void main(String[] args) throws Exception{
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
String str1;
String str2;
while ((str1 = reader.readLine()) != null) {
str2 = reader.readLine();
if (str1.length() < str2.length()) {
System.out.println(getMaxSubstr(str1, str2));
} else {
System.out.println(getMaxSubstr(str2, str1));
}
}
}
}
