#include <bits/stdc++.h>
using namespace std;
#define inf (pow(10,18))
#define ll long long int 
#define mod 1000000007
#define ntq(z)  long long int z; cin>>z; for(long long int i=0;i<z;i++)
#define fi(x9,y9) for(long long int i=x9;i<y9;i++)
#define fj(x9,y9) for(long long int j=x9;j<y9;j++)
#define fk(x9,y9) for(long long int k=x9;k<y9;k++)
#define f(z9) for(long long int i=0;i<z9;i++)
#define endl "\n"
#define sz(a) int((a).size())
#define pb push_back
#define all(c) (c).begin(),(c).end()
#define tr(c,i) for(typeof((c).begin() i = (c).begin(); i != (c).end(); i++)
#define present(c,x) ((c).find(x) != (c).end())
#define cpresent(c,x) (find(all(c),x) != (c).end())
#define stoi(s,n) stringstream str(s); str >> n;
#define get_vi(v, n) vi v(n); f(n){cin >> v[i];}
 
typedef vector< ll > vi;
typedef vector< pair<ll,ll> > vp;
typedef vector< vi > vvi;
typedef pair< ll,ll > ii;

void printprecise(double l,ll precision) {
    std::cout << std::fixed;
    std::cout << std::setprecision(precision);
    std::cout << l;
}

ll ncr(ll n, ll k) 
{ 
    ll C[n + 1][k + 1]; 
    ll i, j; 
    for (i = 0; i <= n; i++) 
    { 
        for (j = 0; j <= min(i, k); j++) 
        { 
            if (j == 0 || j == i) 
                C[i][j] = 1; 
  
            else
                C[i][j] = C[i - 1][j - 1] + 
                          C[i - 1][j]; 
        } 
    } 
  
    return C[n][k]; 
}


ll power_wm(ll x, ll y, ll p) { 
    ll res = 1;      // Initialize result 

    x = x % p;  // Update x if it is more than or  
                // equal to p 

    while (y > 0) 
    { 
        // If y is odd, multiply x with result 
        if (y & 1) 
            res = (res * x) % p; 

        // y must be even now 
        y = y >> 1; // y = y/2 
        x = (x * x) % p;   
    } 
    return res; 
}


ll power(ll x, ll y) { 
    ll res = 1;      // Initialize result 


    while (y > 0) 
    { 
        // If y is odd, multiply x with result 
        if (y & 1) 
            res = (res * x); 

        // y must be even now 
        y = y >> 1; // y = y/2 
        x = (x * x);   
    } 
    return res; 
}


ll root(ll x,vi &roots){
  if(roots[x]!=x)
    roots[x]=root(roots[x],roots);
  return roots[x];
}


void unoin(ll p, ll q,vi &roots,vi &rank){
  ll rp=root(p,roots);
  ll rq=root(q,roots);
  if(rank[rq]<rank[rp]){
    roots[rq]=rp;
  }
  else if(rank[rp]>rank[rq]){
    roots[rp]=rq;
  }
  else{
    roots[rp]=rq;
    rank[rq]++;
  }
  
}


ll dig_sum(ll n) {
  ll s = 0;
  while(n) {
    s += n%10;
    n /=10;
  }
  return s;
}

ll gcd(ll a, ll b) {
    if(a < b) {
      a = a + b;
      b = a - b;
      a = a - b;
    }
    if (b == 0) 
      return a; 
    return gcd(b, a % b); 
}


ll toD(ll x, ll y, ll m) {
  return x*m + y%m;
}


pair <ll, ll> twoD(ll p, ll m) {
  return (make_pair(p/m, p%m));
}

vi parentof,vis,dist;
vvi g;

void dfs(int p) {

  vis[p] = 1;
  f(g[p].size()) {
    if(vis[g[p][i]] == 0) {
      parentof[g[p][i]] = p;
      dist[g[p][i]] = dist[p] + 1;
      dfs(g[p][i]);
    }
  }
}



int main() {
   
  ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
  
  string s, t;

  cin >> s >> t;

  ll m = s.length(), n = t.length();

  vvi lcs(m+1, vi (n+1));

  fi(1, m+1) {
    fj(1, n+1) {
      if(s[i-1] == t[j-1]) {
        lcs[i][j] = lcs[i-1][j-1] + 1; 
      } else {
        lcs[i][j] = max(lcs[i-1][j], lcs[i][j-1]);
      }
    }
  }

  stack <char> st;

  ll i = m, j = n;

  while(i*j > 0) {
    if(s[i-1] == t[j-1]) {
      st.push(s[i-1]);
      i--, j--;
    } else if(lcs[i-1][j] > lcs[i][j-1]) {
      i--;
    } else {
      j--;
    }
  }

  while(!(st.empty())) {
    cout << st.top();
    st.pop();
  }
  
  return 0;
}

Measured memory_bytes: 70784