#include <iostream>
#include <string>
#include <vector>
using namespace std;
int tinh(const string&s1,const string&s2) {
    vector<int> d(10,0); 
    for (char c:s1) {
        if (isdigit(c)) {
            d[c-'0']++;
        }
    }
    for (char c:s2) {
        if (isdigit(c)) {
            d[c-'0']++;
        }
    }
    int r=0;
    for (int i=9;i>=0;i--) {
        if (d[i]>=2) {
            r=r*10+i;
        }
    }
    return r;
}
int main() {
    string s1,s2;
    cin>>s1>>s2;
    int kq=tinh(s1,s2);
    cout<<kq;
    return 0;
}

#include <bits/stdc++.h>
using namespace std;
int cnt[15],cnt2[15];
signed main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	string a,b;
	cin>>a>>b;
	for(int i=0; i<a.size(); i++) {
		if(a[i]>='0'&&a[i]<='9')cnt[a[i]-'0']++;
	}
	for(int i=0; i<b.size(); i++) {
		if(b[i]>='0'&&b[i]<='9')cnt2[b[i]-'0']++;
	}
	string ans="";
	for(int i=9; i>=0; i--) {
		if(cnt[i]&&cnt2[i]) { //cnt[i] co nghia la cnt[i]>0&&cnt2[i]>0
			ans=ans+char(i+'0');
		}
	}
	if(ans.empty())cout<<0;
	else cout<<ans;
}