#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cstring>
#include<string>

using namespace std;

string a, b;

int main()
{
    cin >> a >> b;
    reverse(a.begin(), a.end());
    reverse(b.begin(), b.end());
    cout << (a > b ? a : b) << endl;
    return 0;
}