#include<bits/stdc++.h>

using namespace std;

int main() {
    string s, t;
    cin >> s >> t;
    if (s > t) {
        cout << "abcdefghijklmnopqrstuvwxyz" << endl;
    } else if (s == t) {
        cout << "abcdefghijklmnopqrstuvwxyz" << endl;
    } else {
        cout << "zyxwvutsrqponmlkjihgfedcba" << endl;
    }
    return 0;
}