/in/foo.cc: In function 'int main()':
/in/foo.cc:9:9: warning: unused variable 'famNum' [-Wunused-variable]
  int n, famNum = 0;
         ^~~~~~
/in/foo.cc:34:15: warning: 'cnt' may be used uninitialized in this function [-Wmaybe-uninitialized]
  std::cout << cnt << std::endl;
               ^~~