---

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

int main() {
    int n1, n2;
    string s1, s2;
    cin >> n1 >> n2;
    cin.ignore();
    getline(cin, s1);
    getline(cin, s2);

    n1 = min(n1, (int)s1.size());
    n2 = min(n2, (int)s2.size());

    string s3 = s1.substr(0, n1) + s2.substr(s2.size() - n2);
    cout << s3 << endl;
}