1
#include<bits/stdc++.h>
2
using namespace std;
3

4
map<char, int> nd, win;
5
string s, t;
6
string res;
7

8
int check() {
9
    for(auto& [c, cnt] : nd) {
10
        if(win[c] < cnt) return 0;
11
    }
12
    return 1;
13
}
14

15
int main() {
16

17
    cin >> s >> t;
18

19
    int m = s.size();
20
    int n = t.size();
21

22
    for(auto& c : t) nd[c] ++;
23

24
    int l = 0, r = 0;
25
    int resl = 0, mlen = 1e9;
26

27
    while(r < m) {
28
        win[s[r]] ++;
29

30
        while(check()) {
31

32
            if(r - l + 1 < mlen) {
33
                mlen = r - l + 1;
34
                resl = l;
35
            }
36

37
            win[s[l]] --;
38
            l ++;
39
        }
40

41
        r ++;
42
    }
43

44
    if(mlen == 1e9) res = "";
45
    else res = s.substr(resl, mlen);
46

47
    cout << res << "\n";
48

49
    return 0;
50
}