classSolution {

stringgcdOfStrings(string str1, string str2) {

string shortest, longest;

if(str1.length() < str2.length()){

shortest = str1;

longest = str2;

}

else{

shortest = str2;

longest = str1;

}

string solution ="";

ushort shortest_length = shortest.length();

ushort longest_length = longest.length();

for(ushort i = shortest_length; i >0; --i)

{

if (longest_length % i !=0 || shortest_length % i !=0)continue;

for(ushort j =0; j < longest_length; ++j)

{

ushort first_pointer = j % i;

ushort second_pointer = j % shortest_length;

if(shortest[first_pointer] != longest[j] || shortest[second_pointer] != longest[j])

{

solution ="";

break;

}

if(first_pointer == j) solution += longest[j];

}

if(solution !="")return solution;

}

return"";

}

};