#include <iostream>
#include <vector>
#include <string>
using namespace std;
 
 
int main() {
    
    vector<string> a1;
    a1.push_back("AA");
    a1.push_back("BB");
    vector<string> a2;
    a2.push_back("CC");
    vector<string> a3;
    a3.push_back("DD");
    a3.push_back("EE");
    a3.push_back("FF");
    vector<string> a4;
    a4.push_back("GG");

   for (unsigned int i1 = 0; i1 < a1.size(); ++i1)
        for (unsigned int i2 = 0; i2 < a2.size(); ++i2)
            for (unsigned int i3 = 0; i3 < a3.size(); ++i3)
                for (unsigned int i4 = 0; i4 < a4.size(); ++i4)
                    cout << a1[i1] << " " << a2[i2] << " " << a3[i3] << " " << a4[i4] << std::endl;



    
        return 0;
}