#include <iostream>
#include <string>
using namespace std;

int main() {
    // read in Ann's and Ben's lists
    string ann, ben;
    cin >> ann >> ben;

    // initialize variables for the merged list
    string merged = "";
    int i = 0, j = 0;

    // merge Ann's and Ben's lists
    while (i < ann.length() && j < ben.length()) {
        if (ann[i] < ben[j]) {
            merged += ann[i];
            i++;
        } else {
            merged += ben[j];
            j++;
        }
    }
    while (i < ann.length()) {
        merged += ann[i];
        i++;
    }
    while (j < ben.length()) {
        merged += ben[j];
        j++;
    }

    // output the merged list
    cout << merged << endl;

    return 0;
}