What is supposed to be the output of this?Code:int main() { string s = "12a34b56c78d"; int size = 12; writeStuff(s,size); return 0; } // end main void writeStuff(string s, int size) { if (size > 0) { cout << s.substr(size-1, 1); writeStuff(s, size-3); } // end if } // end writeStuff