#include<bits/stdc++.h>

#define INF 1000000000
#define MOD 1000000007
#define pb push_back
#define f first
#define s second
#define mp make_pair

using namespace std;
const long long MAXN = 3 * 1e4 + 10;
typedef long long ll;
typedef long double ld;
typedef vector <int> vi;
typedef pair <int, int> pii;

void fastIO(){
	ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
	#ifdef LOCAL
   		freopen("input.txt", "r", stdin);
    	freopen("output.txt", "w", stdout);
   	#else
   		freopen("sufprefix.in", "r", stdin);
       freopen("sufprefix.out", "w", stdout);
    #endif
}

string s, t, p;
int pref[MAXN];

void pref_func(string gg){
	for(int i = 1; i < (int)gg.size(); i++){
		int j = pref[i - 1];
		while(j > 0 && gg[i] != gg[j])
			j = pref[j];
		if(gg[i] == gg[j])
			j++;
		pref[i] = j;
	}
}

int main() {
	fastIO();
	cin >> s >> t;
	p = t + '!' + s;
	pref_func(p);
	for(int i = 0; i < pref[s.size() + t.size()]; i++)
		cout << t[i];

	return 0;
}