/in/foo.cc: In function 'int main()':
/in/foo.cc:70:13: warning: 'ans.node::Num' may be used uninitialized in this function [-Wmaybe-uninitialized]
  ans.Num *= n;
             ^
/in/foo.cc:33:11: warning: 'ans.node::Den' may be used uninitialized in this function [-Wmaybe-uninitialized]
  a.Den /= t;
           ^
/in/foo.cc:58:7: note: 'ans.node::Den' was declared here
  node ans, a, b;
       ^~~