#include <iostream>
using namespace std;

char *strcat2 (char *dest, const char *src)
{
    // ADD CODE HERE
};

int main()
{
    char s1[20] = "first";
    char s2[20] = "second";
    cout << s1 << endl << s2 << endl;
    strcat (s1, s2);
    //strcat2 (s1, s2);
    cout << s1 << endl << s2 << endl;
    return 0;
}