#include <bits/stdc++.h>
#include <unordered_map>
#include <unordered_set>
using namespace std;

/*** Template Begins ***/

typedef long long    ll;
typedef pair<ll,ll>  pll;
typedef pair<ll, pair<int, int> > plll;
typedef vector<long long>  vll;
typedef vector<pll>  vp;

#define pb           push_back
#define INF          INT_MAX/10
#define F            first
#define S            second
#define mp           make_pair
#define ios          ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL)
#define hell         1000000007
#define all(a)       (a).begin(),(a).end()
ll power(ll x, ll y, ll p){ ll res = 1;x = x % p;while (y > 0){ if (y & 1) res = (res*x) % p;y = y>>1;x = (x*x) % p;} return res; } 

// Debug //

#define trace(x)                 cerr << #x << ": " << x << endl;
#define trace1(x)                cerr << #x << ": " << x << endl;
#define trace2(x, y)             cerr << #x << ": " << x << " | " << #y << ": " << y << endl;
#define trace3(x, y, z)          cerr << #x << ": " << x << " | " << #y << ": " << y << " | " << #z << ": " << z << endl;
#define trace4(a, b, c, d)       cerr << #a << ": " << a << " | " << #b << ": " << b << " | " << #c << ": " << c << " | " << #d << ": " << d << endl;
#define trace5(a, b, c, d, e)    cerr << #a << ": " << a << " | " << #b << ": " << b << " | " << #c << ": " << c << " | " << #d << ": " << d << " | " << #e << ": " << e << endl;
#define trace6(a, b, c, d, e, f) cerr << #a << ": " << a << " | " << #b << ": " << b << " | " << #c << ": " << c << " | " << #d << ": " << d << " | " << #e << ": " << e << " | " << #f << ": " << f << endl;

// Constants //

const int N = 1e5+7;
const int xinc[] = {0, 0, 1, -1};
const int yinc[] = {1, -1, 0, 0};

/*** Template Ends ***/
std::vector<string> p;


void lcs( string X, string Y, int m, int n ) 
{ 
   int L[m+1][n+1]; 
  
   /* Following steps build L[m+1][n+1] in bottom up fashion. Note 
      that L[i][j] contains length of LCS of X[0..i-1] and Y[0..j-1] */
   for (int i=0; i<=m; i++) 
   { 
     for (int j=0; j<=n; j++) 
     { 
       if (i == 0 || j == 0) 
         L[i][j] = 0; 
       else if (X[i-1] == Y[j-1]) 
         L[i][j] = L[i-1][j-1] + 1; 
       else
         L[i][j] = max(L[i-1][j], L[i][j-1]); 
     } 
   } 
  
   // Following code is used to print LCS 
   int index = L[m][n]; 
  
   // Create a character array to store the lcs string 
   char lcs[index+1]; 
   lcs[index] = '\0'; // Set the terminating character 
  
   // Start from the right-most-bottom-most corner and 
   // one by one store characters in lcs[] 
   int i = m, j = n; 
   while (i > 0 && j > 0) 
   { 
      // If current character in X[] and Y are same, then 
      // current character is part of LCS 
      if (X[i-1] == Y[j-1]) 
      { 
          lcs[index-1] = X[i-1]; // Put current character in result 
          i--; j--; index--;     // reduce values of i, j and index 
      } 
  
      // If not same, then find the larger of two and 
      // go in the direction of larger value 
      else if (L[i-1][j] > L[i][j-1]) 
         i--; 
      else
         j--; 
   } 
  
 
   cout << lcs; 
} 
void solve()
{
  string s,t;
  ll m,n,i,j;
  cin>>s>>t;
  m = s.length(),n=t.length();
  lcs(s,t,m,n);
}
  
int main(){
  
  ios;
  // freopen("input.txt", "r", stdin);
  // freopen("output.txt", "w", stdout);
  int t;
  //cin >> t;
  t = 1;
  while(t--)
    solve();

  return 0;
}

Measured memory_bytes: 35456