 Complete the following phrase:  Sergey Alexandrovich Mozgov ; born 10 March 1995 is a Russian retired competitive ice dancer. With former partner Betina Popova, he is the 2017 CS Warsaw Cup champion. With former partner Anna Yanovskaya, he was the 2015 World Junior champion, two-time 2013, 2014 JGP Final champion, the 2012 Youth Olympics champion, the 