 Complete the following phrase:  Mammadov was born on October 18, 1950 in Khojaly, Azerbaijan. He graduated from the Mathematics Department of Azerbaijan State Pedagogical University and Academy of Public Administration. Since 1973, he worked as a teacher, assistant director and director at a school in Khojaly. In 19851987, he was the head of party organization at dairy sovkhoz. In 19871991, he was the chairman of Khojaly Executive Committee. In 19912000, he was the Mayor of Khojaly, 